Author name code: bappu ADS astronomy entries on 2022-09-14 author:"Bappu, M.K.V." OR author:"Vainu Bappu, M. K." ------------------------------------------------------------------------ Title: VizieR Online Data Catalog: Hydrogen-Line Absorption in Early-Type Stars (Bappu+ 1962) Authors: Bappu, M. K. V.; Chandra, S.; Sanwal, N. B.; Sinvhal, S. D. Bibcode: 1996yCat.2040....0B Altcode: Photoelectric determinations of H-γ absorption line intensity have been made of stars in selected clusters and associations as well as in the general galactic field. Interference filters having a width at half intensity of 45Å were used to isolate spectral regions centered on 4280Å, H-γ and 4410Å. The Γ indices derived, which represent a measure of H-γ absorption, can be used in conjunction with unreddened values of either (U-B) or (B-V) for spectral and luminosity class determinations of stars in the spectral range O6 to A0.

(1 data file). Title: Cosmic perspectives : essays dedicated to the memory of M.K.V. Bappu Authors: Bappu, M. K. V.; Biswas, S. K.; Mallik, D. C. V.; Vishveshwara, C. V. Bibcode: 1989cped.book.....B Altcode: 1989QB51.C74....... No abstract at ADS Title: A survey of red stars in the direction of the Large Magellanic Cloud.III. Some regions north of the bar. Authors: Bappu, M. K. V.; Parthasarathy, M.; Scaria, K. K. Bibcode: 1985KodOB...5....1B Altcode: The authors have continued the survey for red stars in the direction of the Large Magellanic Cloud using the technique of ultra-low dispersion spectroscopy. In this paper they list 310 red stars located north of the LMC bar. Finding charts and coordinates on the Hodge-Wright Atlas Charts are provided. Title: REPORTS FROM ASTRONOMICAL CENTRES: Indian Institute of Astrophysics Authors: Bappu, M. K. V. Bibcode: 1984BASI...12..269B Altcode: No abstract at ADS Title: REPORTS FROM ASTRONOMICAL CENTRES: Indian Institute of Astrophysics Authors: Bappu, M. K. V. Bibcode: 1984BASI...12..293B Altcode: No abstract at ADS Title: Ca II emission in Canopus. Authors: Bappu, M. K. V.; Mekkaden, M. V.; Kameswara Rao, N. Bibcode: 1984BASI...12...64B Altcode: No abstract at ADS Title: CA II K emission in Canopus. Authors: Bappu, M. K. V.; Mekkaden, M. V.; Rao, N. K. Bibcode: 1984BASI...12..196B Altcode: 1984BASI...12..196M The changes in the Ca II K line profile of the F0 supergiant Canopus have been studied from the high dispersion coude spectrograms obtained since 1975. The emission in the core of the line is variable in a timescale of few days. Similar activity seems to be occurring in Mg II h and k lines also. This is attributed to the variability in the appearance of plage areas on the stellar surface. Title: Distribution of Bhb-Stars in the Cluster Omega-Centauri and its Effect on the Radial Change in Colour and Ellipticity of the Cluster Authors: Scaria, K. K.; Bappu, M. K. V. Bibcode: 1984aprm.conf..449S Altcode: The authors have studied the radial change in the distribution of giant branch stars and the horizontal branch stars in ω Centauri. They show how the observed change in the distribution is related to the radial change in the colour of the cluster and also the radial change in its ellipticity. Title: The absolute magnitudes of the Wolf-Rayet stars HD 151932 and HD 152270. Authors: Shylaja, B. S.; Bappu, M. K. V. Bibcode: 1983KodOB...3..104S Altcode: The absolute visual magnitudes of two Wolf-Rayet stars HD 151932 (WN 7) and HD 152270 (WC 7+O8) have been determined from their energy distributions and monochromatic magnitudes least contaminated by emission lines taking into account their membership with the open cluster NGC 6231. Title: Understanding the Universe. The impact of space astronomy. Based on talks given at the UN/IAU International Seminar on the Occasion of UNISPACE 82, Hofburg, Vienna, Austria, 12 August 1982. Authors: West, R. M.; Bappu, M. K. V.; Pal, Y.; Massevitch, A. G. Bibcode: 1983uuis.book.....W Altcode: No abstract at ADS Title: Eclipse observations of coronal emission lines. I - Forbidden Fe X 6374 A profiles at the eclipse of 16 February 1980 Authors: Singh, J.; Saxena, A. K.; Bappu, M. K. V. Bibcode: 1982JApA....3..249S Altcode: Coronal spectra during the total solar eclipse of February 16, 1980, obtained in the 6374 A (forbidden Fe X) line using a multislit spectrograph are discussed. The dispersion of these spectra is 2.5 A/mm. The observed line profiles from 1.1 to 1.7 earth radii, with a spatial resolution of 10 x 22 sq arcsec, yield half-widths that vary from 0.6 A to 2.4 A. A large number of locations are found to have half-widths around 1.3 A, corresponding to a temperature of 4.6 x 10 to the 6th K. If temperatures of the order of 1.3 x 10 to the 6th K are typical of the regions that emit in the forbidden Fe X, then turbulent velocities of approximately 30 km/s are required for the enhanced line broadening. The line-of-sight velocities measured are found to range from +14 km/sec to -17 km/sec. The velocities of most of the locations are less than + or - 5 km/s. It is concluded that the corona does not show any localized differential mass motion and that it co-rotates with the photospheric layers deeper down. Title: Chromospheric activity of late-type giants and supergiants: reappearance of dynamo activity in the interior due to the spin-up of the core in evolution. Authors: Uchida, Y.; Bappu, M. K. V. Bibcode: 1982JApA....3..277U Altcode: The renewal of chromospheric activity in red giants and supergiants is interpreted in terms of the reappearance of dynamo activity in the interior due to the spin-up of the core caused by its contraction in the course of evolution from the main sequence to the giant stage. Title: REPORTS FROM ASTRONOMICAL CENTRES: Indian Institute of Astrophysics Authors: Bappu, M. K. V. Bibcode: 1982BASI...10..165B Altcode: No abstract at ADS Title: Membership of faint galactic clusters. Authors: Bappu, M. K. V.; Babu, G. S. D. Bibcode: 1982BASI...10...41B Altcode: No abstract at ADS Title: The sun is a star Authors: Bappu, M. K. V. Bibcode: 1982sis..book.....B Altcode: No abstract at ADS Title: Corrigendum Authors: Scaria, K. K.; Bappu, M. K. V. Bibcode: 1981JApA....2....7S Altcode: No abstract at ADS Title: Mass segregation in globular clusters Authors: Scaria, K. K.; Bappu, M. K. V. Bibcode: 1981JApA....2..215S Altcode: Photoelectric and photographic techniques are used to study the color changes indicative of segregation effects over the cluster omega-Cen and 47 Tuc. It is established that omega Cen is bluer between 2 arcmin and 4 arcmin from the center, than anywhere else, the B-I color difference between the center and this blue zone being equal to about 0.45 mag. Equidensitometry of omega-Cen in B, V, and infrared bands indicates a wavelength dependence, with the cluster nearly spherical in the infrared band. The blue in this zone comes from both a diffuse background of unresolved stars and an increase in the relative abundance of horizontal branch stars. Results of equidensitometry of the cluster 47 Tuc show that ellipticity is increased with an increase in the blueness of the cluster, and is dependent on the distance from the center. It is suggested that, compared to the nearly spherical distribution of red stars in globular clusters, blue stars form a bulge around the core with a more elliptical distribution and a different orientation. Title: Presence of MG II emission in R CrB at maximum light. Authors: Kameswara-Rao, N.; Nandy, K.; Bappu, M. K. V. Bibcode: 1981MNRAS.195P..71K Altcode: 1981MNRAS.195P..71R The high dipersion spectrum of R CrB in the long wavelength obtained near its maximum with the International Ultraviolet Explorer shows the presence of chromospheric Mg II emission. For comparison the spectrum of Gamma Cyg was obtained immediately afterwards. The Mg II emission width of R CrB is found to be the same as that of Gamma Cyg. Title: REPORTS FROM ASTRONOMICAL CENTRES: Indian Institute of Astrophysics Authors: Bappu, M. K. V. Bibcode: 1981BASI....9..151B Altcode: No abstract at ADS Title: Occultation of BD -19 4222 by Uranus Authors: Bappu, M. K.; Liller, W.; Pande, M. C.; Mehra, H. S.; Pande Vijaymohan, A. K.; Joshi, U. C. Bibcode: 1981IAUC.3599....2B Altcode: M. K. Bappu, Indian Institute of Astrophysics; and W. Liller, Harvard College Observatory, report that the Apr. 26 occultation of BD -19 4222 by Uranus (cf. Klemola et al. 1981, A.J. 86, 138) was successfully observed with the 0.8-m and 1.0-m reflectors at the Kavalur Observatory. While scattered clouds hampered observations of the early portion of the event, clearing skies permitted positive identification of the epsillon-ring occultation at 20h38m37s UT and probably of several other occultations also. M. C. Pande, Uttar Pradesh State Observatory, reports that the occultation by Uranus was successfully observed at Naini Tal by H. S. Mehra, A. K. Pande Vijaymohan and U. C. Joshi using a 1.0-m reflector with EMI 9658 multiplier and a filter combination having a peak response wavelength of 750 nm. The occultation lasted for 19.9 min centered at 19h54m.4 UT. Occultations by the epsillon ring were recorded at 19h18m42s and 20h28m15s UT and were of durations 5s and 3s, respectively. Title: A dependence on solar cycle of the size of the CA+ network Authors: Singh, J.; Bappu, M. K. V. Bibcode: 1981SoPh...71..161S Altcode: Calcium network diameters are shown to be smaller by 5% at solar maximum than at minimum. The average cell size at minimum is 22 115 ± 99 km. The average size at solar maximum is 20 920 ± 112 km, though individual maxima perform differently from each other depending probably on the dispersed remnant magnetic fields. The change in size of the network is interpreted in terms of changes in the size of the supergranular convective cell. Title: Corrigendum - Mass Segregation in Globular Clusters Authors: Scaria, K. K.; Bappu, M. K. V. Bibcode: 1981JApA....2..439S Altcode: No abstract at ADS Title: New Research Journal - Journal of Astrophysics and Astronomy Authors: Bappu, M. K. V. Bibcode: 1981S&T....61R.198B Altcode: No abstract at ADS Title: Emission band and continuum photometry of Comet West /1975n/. II Emission profiles of the neutral coma, lifetimes of molecules and distribution of the molecules and dust within the coma Authors: Bappu, M. K. V.; Parthasarathy, M.; Sivaraman, K. R.; Babu, G. S. D. Bibcode: 1980MNRAS.192..641B Altcode: The scale lengths of the CN and C2 molecules and their parents are derived based on Haser's model from drift scans across the coma of Comet West in the light of CN (0,0), C2 (0,0) and the continuum around 5000 Å. The analysis provides evidence to show that the CN molecules are produced by the dissociation of two species of parent molecules having entirely different lifetimes. A similar result is also obtained for the C2 molecules.

The step scans of 1976 March 19.96, covering the spectral range 3700- 5300 Å and at five independent locations inside the coma show that there is an increase of reddening of the continuum, from the centre of the nucleus outwards. These provide evidence that the coarser particles are to the centre and the finer ones towards the periphery. A study of the radial distribution of CN, C3 and C2 molecules and of the dust particles shows that the C3 (4050 Å) intensities fall most rapidly, compared to CN or C2. Title: Preface Authors: Bappu, M. K. V. Bibcode: 1980JApA....1....1B Altcode: No abstract at ADS Title: Emission band and continuum photometry of Comet West /1975n/. I - Heliocentric dependence of the flux in the emission bands and the continuum Authors: Sivaraman, K. R.; Babu, G. S. D.; Bappu, M. K. V.; Parthasarathy, M. Bibcode: 1979MNRAS.189..897S Altcode: Spectrum scans of the coma of Comet West (1975n) covering the range λλ3700--5700 Å were made on eight nights when the heliocentric distance of the comet varied from 0.588 to 0.853 AU. These have been used to derive the absolute flux in the CN(0,0), C3(4050), C2(1, 0) and C2(0, 0) bands as well as in the continuum. Enhancements in the band emissions were noticed on three nights in CN(0,0), C3(4050) and C2(1, 0). The column densities of neutral sodium atoms are derived from scans around 5900 Å on four nights. The column densities of CO+ ions corresponding to four prominent band sequences are evaluated from two scans of the tail. Title: Extended Ring System of Uranus Authors: Bhattacharyya, J. C.; Bappu, M. K. V.; Mohin, S.; Mahra, H. S.; Gupta, S. K. Bibcode: 1979M&P....21..393B Altcode: Two photoelectric records of the occultation event on 10 March, 1977, obtained by two 102-cm-aperture telescopes, spaced 1500 km apart, are critically analysed and indications of a complex structure of distribution of occulting material surrounding the planet are obtained. The results confirm the existence of a very shallow broad ring system with local condensation lanes of narrow and intermediate widths. A system of numerous thin rings are also present around the planet in the equatorial plane. Title: Radiation and Structure of the Solar Atmosphere Authors: Bappu, M. K. V. Bibcode: 1979IAUTA..17b..49B Altcode: 1979IAUT...17...49B No abstract at ADS Title: Emission band and continuum photometry of comet West (1975n). Authors: Babu, G. S. D.; Bappu, M. K. V.; Parthasarathy, M.; Sivaraman, K. R. Bibcode: 1978BASI....6R..51B Altcode: No abstract at ADS Title: Violet absorption edges of C IV lines in Wolf-Rayet spectra: possible superposition with diffuse interstellar bands at 5780 Å and 5797 Å. Authors: Giridhar, S.; Bappu, M. K. V. Bibcode: 1978KodOB...2..161G Altcode: No abstract at ADS Title: On some photographic aids for the measurement of astronomical spectra Authors: Bappu, M. K. V. Bibcode: 1978mtap.conf..263B Altcode: No abstract at ADS Title: A survey of red stars in the direction of the Large Magellanic Cloud. 2. Some regions around the bar. Authors: Bappu, M. K. V.; Parthasarathy, M.; Scaria, K. K. Bibcode: 1978KodOB...2..184B Altcode: No abstract at ADS Title: The astronomical seeing at Kavalur. Authors: Bappu, M. K. V.; Mohin, S.; Unnikrishnan, K. G. Bibcode: 1978KodOB...2..168B Altcode: No abstract at ADS Title: Saturn-like ring system around Uranus Authors: Bhattacharyya, J. C.; Bappu, M. K. V. Bibcode: 1977Natur.270..503B Altcode: OBSERVATIONS made at Kavalur1,2 of the occultation of SAO158687 by Uranus on 10 March 1977 showed, in addition to the occultation by a satellite system termed the ɛ ring, a dimming of the light of the star close to the time when the atmosphere of the planet could have caused the phenomenon. Since then, the identities of the α, β, γ, δ rings have also become well established, and a theoretical interpretation of their origin3 has been proposed. We have closely examined the Kavalur photoelectric record and describe here several new features of the satellite ring system of Uranus. Title: Indian Institute of Astrophysics. Report for the year 1975 April 1 to 1976 March 31. Authors: Bappu, M. K. V. Bibcode: 1977QJRAS..18..396B Altcode: No abstract at ADS Title: Prominences Authors: Bappu, M. K. V. Bibcode: 1977QJRAS..18..286B Altcode: No abstract at ADS Title: Possible Occultations by Uranian Rings Authors: McCrosky, R. E.; Klemola, A. R.; Shao, C. -Y.; Marsden, B. G.; Elliot, J. L.; Kozai, Y.; Tomita, K.; Bappu, M. K. V. Bibcode: 1977IAUC.3068....1M Altcode: R. E. McCrosky, Center for Astrophysics, has pointed out that two stars of magnitude 11-12 come close to being occulted by the Uranian rings at the end of May. A. R. Klemola, Lick Observatory, has measured the accurate positions of the stars on a recent plate taken with the 51-cm double astrograph, and he confirms that no other stars of magnitude ~ 14 or brighter will be within some 10" of the center of Uranus during the next three months. These positions have mean errors of perhaps +/- 0".2 and were reduced to the FK4 system with the help of 34 SRS positions (kindly telexed by L. Kohoutek, Hamburg Observatory) from the new Perth 70 star catalogue. The indicated near-occultation times, star positions, and also approximate magnitudes and spectral types (the latter derived by C.-Y. Shao from the Palomar Sky Survey prints) are as follows: 1977 UT Star R.A. (1950) Decl. Mag. Sp. May 29.99 AC 1420-13:127 14 23 52.79 -13 48 36.4 12 A 31.27 AC 1420-13:123 14 23 42.42 -13 47 46.5 11.5 F Computations by B. G. Marsden suggest that the stars, which have their closest approaches to Uranus in p.a. 18o, will not be occulted by the epsilon ring (radius 4".0); but as J. L. Elliot, Cornell University, has pointed out, there could be as yet undetected rings up to ~ 5" from Uranus. Local circumstances for the minimum separations are: Location UT Sep. UT Sep. Sutherland May 29d23h48m 5"6 - - Herstmonceux 29 23 52 6.2 - - La Plata 29 23 53 5.5 May 31d06h35m 5"8 La Serena 29 23 54 5.5 31 06 35 5.9 Tucson - - 31 06 39 6.3 Wellington - - 31 06 41 5.6 South Pole 29 23 50 5.3 31 06 38 5.5 Y. Kozai, Tokyo Astronomical Observatory, has communicated a photometric tracing recorded by K. Tomita at the Dodaira Station during the period of ring occultations of SAO 158687 on Mar. 10. Unfortunately, the epsilon occultation seems to have occurred during a 0.8-min interruption to observe the sky background. M. K. V. Bappu writes that the times of the Kavalur observations (IAUC 3061; IAUC 3051 for epsilon) should be changed by -3s. Title: Occultation of SAO 158687 by Uranian Rings Authors: Sinvhal, S. D.; Mahra, H. S.; Gupta, S. K.; Bappu, M. K. V.; Marsden, B. G. Bibcode: 1977IAUC.3061....1S Altcode: S. D. Sinvhal, Uttar Pradesh State Observatory, reports that four secondary occultations of SAO 158687 on Mar. 10 were observed by H. S. Mahra and S. K. Gupta with the 104-cm reflector at Naini Tal as shown below. The occultations can be identified with those of Elliot et al. (IAUC 3051) and are therefore denoted accordingly: Event UT Duration Event UT Duration alpha1 20h32m01s 1s gamma1 20h27m19s 1s beta1 20 30 25 1 delta1 20 26 15 1 The observations extended from 20h22m10s (i.e., after the epsilon occultation occurred) to 21h30m UT with a break during 20h27m55s-20h28m40s. M. K. V. Bappu, Indian Institute of Astrophysics, reports that further examination of the Kavalur tracing (cf. IAUC 3048, 3051, 3058) reveals further occultations. He specifies the times with reference to the middle of the epsilon5 event. The analysis below suggests that the time for epsilon5 given on IAUC 3051 is most likely to be correct, so the times for the other occultations become: Event UT Event UT alpha1 20h30m14s gamma1 20h25m44s beta 20 28 43 delta1 20 24 44 On the assumption that the Elliot-et-al. alpha, beta, gamma and delta rings are circular, centered on Uranus and in its equatorial plane, a least-squares adjustment by B. G. Marsden using the 25 available observations (see also IAUC 3051, 3058) yields the radii (in km and with individual mean errors) listed below. The radii corresponding to the other reported rings (using the midtimes specified for the occultations) are also given: Ring Distance Ring Distance alpha3 42 550 delta 48 510 +/- 30 beta3 42 810 epsilon1,3,5 51 790 +/- 10 alpha 44 950 +/- 40 epsilon2,4 51 120 +/- 10 beta 45 890 +/- 30 zeta4 53 720 gamma 47 840 +/- 20 If the time given for epsilon5 on IAUC 3058 is adopted, the distances corresponding to the Kavalur occultations are all increased by ~ 150 km. The western (odd subscripts) and eastern (even subscripts) sections of epsilon show that this ring is significantly asymmetric, but although the p.a. at Uranus of the epsilon1 and epsilon2 events differs by 110o, that of the epsilon1 and epsilon2 events differs by as much as 8o. With the Uranus-occultation duration of 25 (+/- 0.5) min given by Elliot et al. for the Airborne Observatory (IAUC 3048) the radius of Uranus (assumed to have circular cross-section) is 26 450 +/- 70 km. Title: Occultation of SAO 158687 by Uranian Satellite Belt Authors: Elliot, J. L.; Dunham, E.; Mink, D.; Millis, R. L.; Birch, P.; Trout, D.; Feast, M. W.; Churms, J.; Bappu, M. K. V.; Marsden, B. G. Bibcode: 1977IAUC.3051....1E Altcode: J. L. Elliot, E. Dunham and D. Mink, Cornell University, report that their observations from the Kuiper Airborne Observatory show a group of five secondary occultations of SAO 158687 both before and after the star was occulted by Uranus on Mar. 10 (cf. IAUC 3048). They note that the times of the individual secondary occultations are remarkably symmetrical with respect to the occultation by Uranus itself and suggest that the occulting material is therefore confined to specific narrow rings in the 7000-km-wide belt. The events, labeled with Greek letters in order of increasing separation from Uranus, were recorded as follows, where the UT times correspond to the middle of each occultation, and the subscripts 1 and 2 refer to the different (mean) locations of the Airborne Observatory (the altitude of which was 12.5 km), namely, 1: Long. = -82o11', Lat. = -50o20'; 2: Long. = -101o19', Lat. = -50o21'. Event UT Duration Event UT Duration alpha1 20h20m55s 1s alpha2 21h45m52s 1s beta1 20 19 34 1 beta2 21 47 06 1 gamma1 20 16 58 1 gamma2 21 49 45 1 delta1 20 16 03 1 delta2 21 50 39 1 epsilon1 20 11 46 7 epsilon2 21 54 06 4 R. L. Millis, Lowell Observatory, reports that five occultation events were also detected by P. Birch, D. Trout and himself with the 61-cm reflector at the Perth Observatory (cf. IAUC 3048). Mid-times of these events (denoted with subscript 3) are: Event UT Duration Event UT Duration alpha3 20h23m43s 1s delta3 20h15m59s 1s beta3 20 23 19 1 epsilon3 20 10 33 8 gamma3 20 18 44 1-2 M. W. Feast, South African Astronomical Observatory, reports that J. Churms monitored the occultation at Cape Town (subscript 4) and (after learning of the times observed by Elliot et al.) provided the following mid-times for some short-duration events: Event UT Duration Event UT Duration alpha4 21h55m20s - delta4 22h00m13s _ beta4 21 56 38 - epsilon4 22 03 44 6s gamma4 21 59 18 - zeta4 22 07 11 8 These first four events were the only ones of significance (dips of ~ 1 mm on the photometer trace) observed between 21h45m and 22h02m UT. Observations began at 20h40m, but the trace was less steady during the early stages because of low altitude. The epsilon4 event was a major one (amounting to ~ 1 cm on the trace, about as much as the Uranus occultation itself), and the trace was noticeably ragged (dips ~ 1 mm) between 22h02m and 22h05m. The zeta4 occultation had a depth of 3 mm but occurred at the very end of the trace. Feast remarks that the photometer was a conventional (not a high speed) one and that the dips of short duration will not be faithfully reproduced as to their shape. A letter received from M. K. V. Bappu, Indian Institute of Astrophysics, gives the time of the beginning of the occultation observed at Kavalur as 20h19m51s UT (rather than 20h19m15s; cf. IAUC 3048), from which we can define for the middle of the event: Event UT Duration epsilon5 20h19m55s 9s The values correlated below for the distances of the occulting material from the center of Uranus (in km, and projected on the plane of Uranus' equator) were derived by the undersigned. The relative positions of Uranus and the star were adjusted so that the distances for the first four events with subscripts 1 and 2 coincide (the mutual agreement among them being +/- 40 km) and so that the distance for epsilon5 is the mean of those for epsilon1 and 2 (i.e. 51 700 km). Coincidence of the distances for epsilon5 and 1 produces an increase of ~ 600-700 km in the distances of the rings. Event Distance Event Distance Event Distance alpha3 42 200 beta3 42 500 alpha1,2 44 900 alpha4 45 000 beta1,2 45 900 gamma3 45 700 beta4 46 000 gamma1,2 47 900 delta3 47 800 gamma4 48 000 delta1,2 48 600 delta4 48 800 epsilon1 52 000 epsilon3 51 900 epsilon2 51 400 epsilon4 51 600 epsilon5 54 300 Dr. Elliot is planning to make a detailed study of these occultations and would appreciate receiving observations (including photometer tracings). His address is: Center for Radiophysics and Space Research, Cornell University, Ithaca, NY 14853, U.S.A. Title: Occultation of SAO 158687 by Uranus and Satellite Belt Authors: Elliot, J. L.; Dunham, E.; Mink, D.; Millis, R. L.; Birch, P.; Trout, D.; Bappu, M. K. V.; Bhattacharyya, J. C.; Kuppuswamy; Marsden, B. G. Bibcode: 1977IAUC.3048....1E Altcode: Amplifying the brief announcement on IAUC 3047, J. L. Elliot reports that several secondary occultations of SAO 158687 on Mar. 10 were observed by E. Dunham, D. Mink and himself from the Kuiper Airborne Observatory and also by R. L. Millis, P. Birch and D. Trout at the Perth Observatory. Both groups independently concluded that these occultations were caused by bodies that are apparently part of a satellite belt about 40 000 km distant from the center of Uranus. The diameters of the satellites range from 100 km to much smaller values. The occultation by Uranus itself was successfully observed from the Airborne Observatory (located at Long. = -90o, Lat. = -50o) and lasted ~ 25 min centered on 21h06m UT. The Uranus occultation did not occur at the Perth Observatory. The secondary occultations took place during an 8-9 min interval around 20h16m UT and during a similar interval around 21h50m UT (although dawn prevented observations of the latter events in Perth). M. K. V. Bappu, Indian Institute of Astrophysics, cables: "Using the 102-cm reflector at Kavalur (Long. = -5h15m19s.6, Lat. = +12o34'32"), Bhattacharyya and Kuppuswamy found the diminution of SAO 158687 during the occultation by the atmosphere of Uranus to be 0.046 magnitude at an effective wavelength of 7500 A. Visually and photoelectrically they observed the complete disappearance of the star for 8s.9 beginning at 20h19m15s UT and ascribe this to obscuration by a hitherto unknown satellite of the planet." Computations by the undersigned show that the asymmetry in the times of the satellite occultations about the main occultation (as observed at the Airborne Observatory) is consistent with the existence of a circular belt in the plane of Uranus' equator. Allowance for foreshortening yields the radii of the inner and outer edges of the belt as 44 000 and 51 000 km, respectively. The Kavalur observation suggests occultation by a 100-km-sized body near the outer edge of the belt. Other observers are urged to examine their records for further evidence of this belt. At Sutherland, times of mid-occultation by the belt would have been 20h22m and 21h59m UT; at Mauritius, 20h23m and 21h54m; at Lembang, 20h20m and 21h46m; at Kyoto, 20h22m; at Helwan, 21h56m. Those wishing to attempt to detect the satellite belt directly are advised that at the present opposition it should be located from 3".5 to 4".0 to the north and south of the center of Uranus and from 2".7 to 3".1 to the east and west; the brightest bodies in it are expected to have mv ~ 19. Title: K emission line widths in the Sun and the stars. Authors: Bappu, M. K. V.; Sivaraman, K. R. Bibcode: 1977MNRAS.178..279B Altcode: K-emission line widths measured with a micrometer on integrated spectra of the sun have a mean value of 38.2 km/s. A definition is proposed whereby the width is a measure in km/s at the inverse-e value of the difference between the intensity of the brighter K2 peak over the K1 background, reckoned from this latter level. Averaged spectra over different parts of the solar disk show the very appreciable contribution by rotation to the emission line width, making it imperative for any calibration of width with absolute magnitude to use a solar value derived from an integrated spectrum. Arguments are presented showing that the K-emission profile observed in other stars is the profile of the typical bright mottle that should enable the derivation of chromospheric parameters. From measures of Doppler displacements of both K2 and K3, 'dark condensations' as seen on the sun play a role in the atmospheres of stars with K emission. Title: Ultra-low dispersion spectroscopy of stars and galaxies. Authors: Bappu, M. K. V.; Parthasarathy, M. Bibcode: 1977KodOB...2....1B Altcode: No abstract at ADS Title: A survey of red stars in the direction of the Large Magellanic Cloud. 1. The 30 Doradus region. Authors: Bappu, M. K. V.; Parthasarathy, M.; Scaria, K. K. Bibcode: 1977KodOB...2...85B Altcode: No abstract at ADS Title: An automated spectrum scanner. Authors: Bappu, M. K. V. Bibcode: 1977KodOB...2...64B Altcode: No abstract at ADS Title: The Wolf-Rayet spectroscopic binary HD 214419. Authors: Bappu, M. K. V.; Visvanadham, P. Bibcode: 1977KodOB...2...89B Altcode: No abstract at ADS Title: The near-infrared spectra of Wolf-Rayet stars. Authors: Bappu, M. K. V.; Ganesh, K. S.; Scaria, K. K. Bibcode: 1977KodOB...2...28B Altcode: No abstract at ADS Title: Indian Institute of Astrophysics. Authors: Bappu, M. K. V. Bibcode: 1976QJRAS..17..341B Altcode: No abstract at ADS Title: Prominences Authors: Bappu, M. K. V. Bibcode: 1976QJRAS..17...63B Altcode: No abstract at ADS Title: Radiation and structure of the solar atmosphere (Radiation et structure de l'atmosphère solaire). Authors: Giovanelli, R. G.; Mein, P.; Bappu, M. K. V.; Jordan, C.; MacQueen, R. M. Bibcode: 1976IAUTA..16b..55G Altcode: No abstract at ADS Title: Indian Institute of Astrophysics. Report for the year 1973 April 1 to 1974 March 31. Authors: Bappu, M. K. V. Bibcode: 1975QJRAS..16..184B Altcode: No abstract at ADS Title: Prominences Authors: Bappu, M. K. V. Bibcode: 1975QJRAS..16...38B Altcode: No abstract at ADS Title: Book reviews Authors: van de Stadt, Herman; Rawer, Karl; Schadee, A.; Noyes, R. W.; Bleeker, J. A. M.; Wittenberg, H.; de Graaff, W.; Akasofu, S. -I.; Hooykaas, R.; Bappu, M. K. V.; Atanasijević, I.; Icke, Vincent; van der Valk, F.; Kresàk, L.; Müller, Edith A. Bibcode: 1975SSRv...17..159V Altcode: No abstract at ADS Title: Photelectric spectrophotometry of early type stars. Authors: Bappu, M. K. V.; Nandy, K.; Parthasarathy, M.; Rajamohan, R. Bibcode: 1975BASI....3Q..30B Altcode: No abstract at ADS Title: Research with a moderate aperture telescope. Authors: Bappu, M. K. V. Bibcode: 1975oams.conf...35B Altcode: No abstract at ADS Title: Indian Institute of Astrophysics. Report for the year 1972 April 1 to 1973 March 31. Authors: Bappu, M. K. V. Bibcode: 1974QJRAS..15..302B Altcode: No abstract at ADS Title: On detection of QSOs by ultra low dispersion spectroscopy. Authors: Bappu, M. K. V.; Parthasarathy, M. Bibcode: 1974BASI....2...36B Altcode: No abstract at ADS Title: Presidential Address Authors: Bappu, M. K. V. Bibcode: 1974BASI....2...23B Altcode: No abstract at ADS Title: Sodium emission in comet Kohoutek (1973f). Authors: Bappu, M. K. V.; Parthasarathy, M.; Sivaraman, K. R. Bibcode: 1974BASI....2R..35B Altcode: No abstract at ADS Title: The current shell spectrum of Pleione. Authors: Prabhu, T.; Bappu, M. K. V. Bibcode: 1974BASI....2Q..36P Altcode: No abstract at ADS Title: Infrared and millimeter range astronomy. Proceedings of a seminar held at Hyderabad, India, 25_-_26 Februar 1974. Authors: Alladin, S. M.; Abhyankar, K. D.; Bappu, M. K. V. Bibcode: 1974imra.conf.....A Altcode: No abstract at ADS Title: Elliptical galaxies with compact nuclei. Authors: Bappu, M. K. V.; Parthasarathy, M. Bibcode: 1974BASI....2R..37B Altcode: No abstract at ADS Title: Solar Prominences in 1972 Authors: Bappu, M. K. V. Bibcode: 1973QJRAS..14..407B Altcode: No abstract at ADS Title: Indian Institute of Astrophysics. Report for the year 1971 April 1 to 1972 March 31. Authors: Bappu, M. K. V. Bibcode: 1973QJRAS..14..209B Altcode: No abstract at ADS Title: Comet Kohoutek (1973f). Authors: Bappu, M. K. V.; Parthasarathy, M.; Sivaraman, K. R.; Matchett, V. L.; Mayo, M.; Truxton, J.; Sherrod, C. Bibcode: 1973IAUC.2608....1B Altcode: No abstract at ADS Title: On the K-Line Width-Absolute Magnitude Relation Authors: Bappu, M. K. V. Bibcode: 1973IAUS...54...64B Altcode: No abstract at ADS Title: Wolf-Rayet and high-temperature stars proceedings from IAU Symposium no. 49 held in Buenos Aires, Argentina, August 9-14, 1971. Authors: Bappu, M. K. V.; Sahade, Jorge Bibcode: 1973IAUS...49.....B Altcode: No abstract at ADS Title: Photometry of the solar corona of March 7, 1970. Authors: Bappu, M. K. V.; Bhattacharyya, J. C.; Sivaraman, K. R. Bibcode: 1973Prama...1..117B Altcode: No abstract at ADS Title: The Spectra of Wolf-Rayet Stars at High Dispersion Authors: Bappu, M. K. V. Bibcode: 1973IAUS...49...59B Altcode: No abstract at ADS Title: Solar Prominences in 1971 Authors: Bappu, M. K. V. Bibcode: 1972QJRAS..13..525B Altcode: No abstract at ADS Title: On Emission Lines of Hydrogen, Helium and Ionized Calcium Seen on a Coronal Spectrogram of the March 7, 1970 Eclipse Authors: Bappu, M. K. V.; Bhattacharyya, J. C.; Sivaraman, K. R. Bibcode: 1972SoPh...26..366B Altcode: Emission lines of the Balmer series, D3 and H and K are reported present on a coronal spectrogram obtained at the March 7, 1970 eclipse. Arguments are presented to show that these could not have originated from scattering in the Earth's atmosphere and hence possibly have a coronal origin. Title: Kodaikanal Observatory, Kodaikanal. Report for the period January 1970 to March 31, 1971. Authors: Bappu, M. K. V. Bibcode: 1972QJRAS..13..448B Altcode: No abstract at ADS Title: Solar Prominences in 1970 Authors: Bappu, M. K. V. Bibcode: 1972QJRAS..13...70B Altcode: No abstract at ADS Title: Annual report of the Kodaikanal Observatory for the year 1969. Authors: Bappu, M. K. V. Bibcode: 1972arko.book.....B Altcode: No abstract at ADS Title: Optical astronomy in India - prospects of the next decade. Authors: Bappu, M. K. V. Bibcode: 1972CSci...41..829B Altcode: No abstract at ADS Title: K Emission-Line Widths and the Solar Chromosphere Authors: Bappu, M. K. V.; Sivaraman, K. R. Bibcode: 1971SoPh...17..316B Altcode: Closely spaced microphotometer tracings parallel to the dispersion of one excellent frame of a K-line time sequence have been utilized for a study of the nature of the K2v, K2R intensities in the case of the solar chromosphere. The frequency of occurrence of the categories of intensity ratio are as follows: per cent; per cent; per cent; per cent; per cent. Two types of absorbing components are postulated to explain the pattern of observed K2v, k2R intensity ratios. One component with minor Doppler displacements acting on the normal K232 profile, where K2V >K2R, produces the cases K2v ≫ K2R, K2v = K2R, K2v <K2R. The other component arises from `dark condensations' which are of size 3500 kms as seen in K2R. They have principally large down flowing velocities in the range 5-8 km/sec and are seen on K3 spectroheliograms with sizes of about 5000 kms, within the coarse network of emission. These `dark condensations' give rise to the situation K2R = 0. Title: Summary of magnetic and ionospheric observations, January - June, 1968. Authors: Bappu, M. K. V. Bibcode: 1971KodOB.201....1B Altcode: No abstract at ADS Title: Summary of magnetic and ionospheric observations, July - December, 1967. Authors: Bappu, M. K. V. Bibcode: 1971KodOB.199..915B Altcode: No abstract at ADS Title: Summary of solar observations for the second half of 1969. Authors: Bappu, M. K. V. Bibcode: 1971KodOB.207..169B Altcode: No abstract at ADS Title: Summary of magnetic and ionospheric observations, January - June 1966. Authors: Bappu, M. K. V. Bibcode: 1971KodOB.194.....B Altcode: No abstract at ADS Title: Summary of solar observations for the first half of 1969. Authors: Bappu, M. K. V. Bibcode: 1971KodOB.206..141B Altcode: No abstract at ADS Title: Solar activity. Authors: Laurie, P. S.; Bappu, M. K. V. Bibcode: 1970QJRAS..11..219L Altcode: No abstract at ADS Title: Kodaikanal Observatory, Kodaikanal. Report for the year ending 1969 December 31. Authors: Bappu, M. K. V. Bibcode: 1970QJRAS..11..366B Altcode: No abstract at ADS Title: Summary of prominence and calcium flocculus observations, magnetic observations, and ionospheric observations for the first half of 1964. Authors: Bappu, M. K. V. Bibcode: 1970KodOB.174.....B Altcode: No abstract at ADS Title: Summary of prominence and calcium flocculus observations, magnetic data, and ionospheric data for the second half of 1964. Authors: Bappu, M. K. V. Bibcode: 1970KodOB.175.....B Altcode: No abstract at ADS Title: Summary of prominence and calcium flocculus observations, magnetic data, ionospheric data, for the second half of 1969. Authors: Bappu, M. K. V. Bibcode: 1970KodOB.177.....B Altcode: No abstract at ADS Title: Summary of solar observations, January - December 1967. Authors: Bappu, M. K. V. Bibcode: 1970KodOB.196...41B Altcode: 1970KodOB.196..41.B No abstract at ADS Title: Summary of prominence and calcium flocculus observations, magnetic data, and ionospheric data for the first half of 1965. Authors: Bappu, M. K. V. Bibcode: 1970KodOB.176.....B Altcode: No abstract at ADS Title: Annual report of the Kodaikanal Observatory for the year 1968. Authors: Bappu, M. K. V. Bibcode: 1970arko.book.....B Altcode: No abstract at ADS Title: Summary of solar observations, January - June, 1966. Authors: Bappu, M. K. V. Bibcode: 1970KodOB.192.....B Altcode: No abstract at ADS Title: Summary of magnetic and ionospheric observations January - June, 1967. Authors: Bappu, M. K. V. Bibcode: 1970KodOB.198.....B Altcode: No abstract at ADS Title: Kodaikanal Observatory, Kodaikanal. Report for the year ending 1968 December 31. Authors: Bappu, M. K. V. Bibcode: 1969QJRAS..10..317B Altcode: No abstract at ADS Title: Some characteristics of the solar wind inferred from the study of sodium emission from cometary nuclei Authors: Bappu, M. K. V.; Sivaraman, K. R. Bibcode: 1969SoPh...10..496B Altcode: Seventeen comets, having information on sodium D-line emission during their apparition, have been studied. The heliocentric distances corresponding to the sodium emission commencement or termination epoch are found to have a dependence on the phase of the solar cycle. For comets appearing during a solar maximum the sodium emission is detectable out to greater distances than, for the comets appearing during solar minimum. The sodium emission is also found to depend on heliographic latitude of the comet. It is concluded that the spatial properties of the solar wind during a solar maximum and minimum are responsible for the observed dependence. Title: Reports on the progress of astronomy: Solar activity (sunspots, prominences). Authors: Laurie, P. S.; Bappu, M. K. V. Bibcode: 1969QJRAS..10..239L Altcode: No abstract at ADS Title: Kodaikanal Observatory. Report for the year ending 1967 December 31. Authors: Bappu, M. K. V. Bibcode: 1969QJRAS..10...60B Altcode: No abstract at ADS Title: Comet Ikeya-Seki (1965) and the nature of the interplanetary medium during its apparition. Authors: Bappu, M. K. V.; Sivaraman, K. R. Bibcode: 1969KodOB.187.....B Altcode: No abstract at ADS Title: Quasars - Observational Authors: Bappu, M. K. V. Bibcode: 1969crsr.conf..217B Altcode: No abstract at ADS Title: The solar corona of July 20, 1963. Authors: Bappu, M. K. V.; Bhatnagar, A. Bibcode: 1969KodOB.190.....B Altcode: No abstract at ADS Title: An analysis of the cepheid variable RT Aurigae Authors: Bappu, M. K. V.; Raghavan, Nirupama Bibcode: 1969MNRAS.142..295B Altcode: High dispersion spectra of the cepheid variable RT Aurigae have been used for an analysis of the parameters of the stellar atmosphere over a cycle of pulsation. Eighteen of these spectra were utilized for a study of the radial velocities. The displacement curve derived from the velocities was utilized with the light and colour curves of Eggen, Gascoigne & Burr to furnish by the application of Wesselink's method, a value of RIR o = 33.7. A differential curve of growth analysis relative to the Sun has been carried out at eleven phases to evaluate the variation of the atmospheric parameters. The range in Oexe is from to . The variation of K is by a factor of ten over the cycle. A second hump in this curve at phase P is perhaps a result of the sudden onset of a pulse of compression. Mean abundances relative to [Fe] have been derived for 21 elements. A general deficiency in s-process elements is seen in comparison with those formed by the e-process. Title: Summary of prominence and calcium flocculus observations, magnetic data, and ionospheric data for the second half of 1963. Authors: Bappu, M. K. V. Bibcode: 1969KodOB.173.....B Altcode: No abstract at ADS Title: Summary of prominence and calcium flocculus observations, magnetic data, and ionospheric data for the first half of 1963. Authors: Bappu, M. K. V. Bibcode: 1969KodOB.171.....B Altcode: No abstract at ADS Title: Summary of solar observations for the second half of 1968. Authors: Bappu, M. K. V. Bibcode: 1969KodOB.203B.115B Altcode: No abstract at ADS Title: Stellar chromospheres. Authors: Bappu, M. K. V. Bibcode: 1969KodRe..37.....B Altcode: No abstract at ADS Title: Annual report of the Kodaikanal Observatory for the year 1967. Authors: Bappu, M. K. V. Bibcode: 1969arko.book.....B Altcode: No abstract at ADS Title: On the Development of Magnetic Fields in Active Regions Authors: Bappu, M. K. V.; Grigorjev, V. M.; Stepanov, V. E. Bibcode: 1968SoPh....4..409B Altcode: Transverse and longitudinal magnetic field scans together with K232 spectroheliograms that cover the early phases of active region formation reveal the following: The new active region forms near the periphery of an old magnetic region. There is evidence that the new region forms an interrelated system with the old magnetic structures on the sun. Title: Summary of prominence observations, magnetic observations, and ionospheric observations for the second half of 1962. Authors: Bappu, M. K. V. Bibcode: 1968KodOB.169.....B Altcode: No abstract at ADS Title: Chromospheric Heights in Active Regions Authors: Bappu, M. K. V.; Sivaraman, K. R. Bibcode: 1968IAUS...35..247B Altcode: No abstract at ADS Title: Summary of prominence and calcium flocculus observations, magnetic observations, and ionospheric observations for the first half of 1962. Authors: Bappu, M. K. V. Bibcode: 1968KodOB.168.....B Altcode: No abstract at ADS Title: Annual report of the Kodaikanal Observatory for the year 1966. Authors: Bappu, M. K. V. Bibcode: 1968arko.book.....B Altcode: No abstract at ADS Title: Excitation temperatures of the Wolf-Rayet stars Authors: Bappu, M. K. V.; Chitre, S. M. Bibcode: 1968MNRAS.140...71B Altcode: Hydrogenic transitions of C iv are used to derive excitation temperatures for WoIf-Rayet stars of the WC sequence. The line intensities of such transitions in HD 165763, HD 192641, HD 192103 and HD 184738 are derived from measures of equivalent widths on spectra of 10 A/mm and 20 A/mm dispersion. These intensities are corrected for continuum values derived by the method of photoelectric spectrophotometry. This technique of temperature determination yields values of temperature unaffected by non-LTE effects in the Wolf-Rayet atmosphere. The mean values obtained are as follows: HD 165763 (WC6) 569000*26000; HD 192641 (WC7) 516000*63000; HD 192103 (WC7) 373000*34000; HD 184738 (WC8) 240000*4I000K. The intensities of the (4n) series of He ii are used to derive an excitation temperature of the WN7 star HD 192163, using intensities measured on a single high dispersion Mount Wilson coude' spectrogram. The value derived is 32 4000+42000. A Balmer contribution to the emission of the Pickering series is obvious, though the hydrogen emission present is little. Arguments are presented to show that the (5 ) transition 8236 A and the (5-15) transition 6406 A can be utilized on high dispersion spectra for obtaining reliable excitation temperatures of stars of the WN sequence. Title: Monochromatic polarization measures of comet Ikeya-Seki (1965f) Authors: Bappu, M. K. V.; Sivaraman, K. R.; Bhatnagar, A.; Natarajan, V. Bibcode: 1967MNRAS.136...19B Altcode: Monochromatic measures of polarization of Comet Ikeya-Seki (I 965f) at 3 890 A, 4 300 A, 4 740 A and 5 875 A are described. The relative contributions of emission and continuum to radiation transmitted by the fflters at 3 890 A and 4740 A are evaluated. The polarization at phase angle 900 of the CN (o,o) band is 6'9% while that of the C2 (1,0) band is %, in close agreement with the theoretical values for resonance fluorescence. The polarization value of the continuum is % at phase angle 900, while for the same phase angle, a measure of the polarization in the tail, 3' away from the head, is 13' 6%. The agencies responsible for the continuum in both head and tail are likely to have a difference in the major constituent. The role of ices and iron particles as scattering agencies is discussed. - Title: Solar Physics at Kodaikanal Authors: Bappu, M. K. V. Bibcode: 1967SoPh....1..151B Altcode: No abstract at ADS Title: Emission band photometry of comet Ikeya-Seki (1965f) Authors: Bappu, M. K. V.; Sivaraman, K. R. Bibcode: 1967MNRAS.137..151B Altcode: Photoelectric measures of emission band intensities of C2 (I, o) and CN (o, o) of the coma of Comet Ikeya-Seki (1965f) are reported. The measured fluxes are utilized to determine the number of molecules of C2 and CN that contribute to the observed emission. Title: Reports on the Progress of Astronomy: Solar Activity-Prominences Authors: Vainu Bappu, M. K. Bibcode: 1965QJRAS...6..335V Altcode: No abstract at ADS Title: Photoelectric observations of the 1963-1964 eclipse of zeta Aurigae Authors: Bappu, M. K. V.; Doss, A. T.; Viswanadham, P. Bibcode: 1965Obs....85...85B Altcode: No abstract at ADS Title: Solar Activity-Prominences Authors: Vainu Bappu, M. K. Bibcode: 1964QJRAS...5..227V Altcode: No abstract at ADS Title: Solar Activity-Prominences Authors: Vainu Bappu, M. K. Bibcode: 1963QJRAS...4..301V Altcode: No abstract at ADS Title: The influence of superflares in the H alpha striation pattern Authors: Bappu, M. K. V.; Bhatnagar, A.; Punetha, L. M. Bibcode: 1962Obs....82..192B Altcode: No abstract at ADS Title: Calcium faculae and solar flare effects Authors: Bappu, M. K. V.; Punetha, L. M. Bibcode: 1962Obs....82..170B Altcode: No abstract at ADS Title: Photoeletric measures of hydrogen-line absorption in early-type stars. Authors: Bappu, M. K. V.; Chandra, S.; Sanwal, N. B.; Sinvhal, S. D. Bibcode: 1962MNRAS.123..521B Altcode: Photoelectric determinations of H absorption line intensity have been made of stars in selected clusters and associations as well as in the general galactic field. Interference filters having a width at half intensity of 45 A were used to isolate spectral regions centred on 4z80 A, H and 4410 A. The F indices derived, which represent a measure of the Hy absorption, can be used in conjunction with unreddened values of either (U-B) or (B - V) for spectral and luininosity class determinations of stars in the spectral range O6 to Ao. The separation of age loci is shown to exist on F, (U-B)0 diagrams of clusters and associations having different ages. A F, Mv calibration for the young, or less evolved stars, has been derived. Tests of such a calibration have been made on the Orion Association and NGC z362. The distance moduli thus obtained are in good agreement with the values derived from the colour magnitude arrays. Title: Polarization measures of Comet Arend-Roland (1956h) and Comet Mrkos (1957d). Authors: Vainu Bappu, M. K.; Sinvhal, S. D. Bibcode: 1960MNRAS.120..152V Altcode: Measurements of polarization of Comet Arend-Roland and of Comet Mrkbs made photoelectrically, using interference filters and conventional B, V filters are given. The interference filters were chosen to isolate the Na emission at 5890 A and the continuum at 4800 A and 4300 A. The polarization at 4800 A in both comets is similar yielding a mean value of 20 1 per cent computed for a phase angle of 900. This indicates that the agencies responsible for the continuum were identical in both comets. The polarization of Na emission calculated for a phase angle of 900 for Comet Mrkos was per cent in agreement with the theoretical value for Na resonance radiation. Title: Report of proceedings of Uttar Pradesh State Observatory, Naini Tal Authors: Bappu, M. K. V. Bibcode: 1959MNRAS.119..399B Altcode: No abstract at ADS Title: Interference filter photometry of weak emission lines in CQ Cephei Authors: Bappu, M. K. V.; Sinvhal, S. D. Bibcode: 1959Obs....79..140B Altcode: No abstract at ADS Title: The light variation of 6 Cassiopeiae Authors: Bappu, M. K. V. Bibcode: 1959Obs....79..100B Altcode: No abstract at ADS Title: 3. A Physical Analysis of Woif-Rayet Spectra Authors: Vainu Bappu, M. K. Bibcode: 1958LIACo...8...40V Altcode: No abstract at ADS Title: Polarization of Comet Arend-Roland Authors: Bappu, M. K. Vainu; Sinvhal, S. D. Bibcode: 1957Natur.180.1410B Altcode: WHEN, last May, Comet Arend-Roland became a bright naked-eye object in the northern hemisphere, we carried out a series of photoelectric measures of the polarization of its coma at different phase angles. The technique employed utilized a piece of `Polaroid' attached to a rotatable six-position disk contained in the photometer. This enables measurements of intensity to be made as the `Polaroid' is turned through 60 dog. for each position of the disk. Standard B and V filters employed in the UBV system, together with interference filters having peak transmissions centred on 5890 A., 5000 A., 4700 A. and 4300 A. and half-widths of 80 A. were used for isolating the different wave-lengths. Each of the three circular apertures behind the `Polaroid' transmitted 3.7 square minutes of arc of the sky. Title: H and K Emission in Late-Type Stars: Dependence of Line Width on Luminosity and Related Topics. Authors: Wilson, O. C.; Vainu Bappu, M. K. Bibcode: 1957ApJ...125..661W Altcode: The H and K emission lines of Ca II have been studied on 10-A/mm spectrograms of 185 stars of types G, K, and M. Nearly all stars of type G0 or later in the list of MK standards (Johnson and Morgan 1953) have been included. Emission-line widths have been measured, as well as displacements of the emission and absorption components. Tb e displacements are determined with respect to nearby low-excitation reversing- layer absorption lines.

When the logarithms of the emission-line widths (corrected for instrumental width) are plotted against the Yerkes absolute spectroscopic magnitudes, the points define a straight line which extends over a 15-mag. range of Mv and which indicates that the line width varies as the one-sixth power of the luminosity. Stars with weak or strong lines and of all spectral types later than G0 seem to fit the linear relationship equally well. The widths therefore cannot be dependent upon line intensity or stellar surface temperature.

Evidence from the solar spectrum, from ζ Aurigae, from Hyades stars, and from four visual binaries point to the conclusion that the relationship described here is not of a statistical nature. Therefore, it is probable that the Ca II emission-line widths can be used as luminosity indicators. Internal consistency considerations indicate that one good spectrogram should fix the absolute magnitude of any late-type star with suitable lines to within ±05 mag.

It is found that,for displacements within ±6 km/sec, negative values are more frequent than positive for the emission components of H and K. On the other hand, between +4 and -4 km/sec, positive values are more common for the absorption components. The naive interpretation is that the emitting layer is rising and that the absorbing material is falling slowly inward. Statistics of the larger displacements common among the intrinsically luminous stars are discussed briefly. In particular, it is found that among the M-type giants and supergiants the negative displacements of the absorption components are not correlated with absolute magnitude. Title: Spectrophotometry of WoIf-Rayet binary systems. Authors: Bappu, M. K. Vainu; Sinvhal, S. D. Bibcode: 1955AJ.....60..152B Altcode: Spectra obtained at the cassegrain focus of the Mt. Wilson 6o-inch telescope over two seasons of observing have been used to study the variation of emission line intensities and the profiles of a few Wolf-Rayet binary systems. The binaries chosen are HD 214419, HD 193576 and HD 193928 having periods of 1.64, 4.21 and 21.64 days, respectively. Of these three, only two have been known to be eclipsing variables. HD 214419. Hiltner (1950) has found by photoelectric methods that the intensity of Heii 4686 in the binary reaches a maximum during conjunctions and~a minimum at elongations. We have measured equivalent widths at different phases for the lines Heii 6560, Hei 5875, Heii 5411 and Niv 4058. The equivalent widths of all these lines have a pattern of behavior identical to that of Heii 4686, in that all of them show increased intensities at primary and secondary minima with a lower value of intensity at elongations. On certain nights the emission intensity is considerably above average as noted by Hiltner. On such occasions, there is corresponding increase in the intensity of the other lines showing that a change in the general overall excitation mechanism is the responsible agent for the fluctuation. There are no very conspicuous changes with phase in the profiles of X4686 as has been noted in the case of HD 193576. Nearly always at the primary minimum when the Wolf-Rayet star is behind its companion, the X4686 profile has a sharp peak at the centre with wide distended wings. At secondary mini- μm when we receive radiation primarily from the Wolf-Rayet star a well rounded profile results with a slight asymmetry on the long wavelength side. The shapes at primary minimum of the profiles of Heii 4686, Heii 6560, Heii 5411 and Niv 4058 resemble the curves that would result, were the profiles outside eclipse modified by electron scattering. There is evidence that the half-widths of Niv 4058 increase at primary minimum. Such a result may be obtained if self-reversal effects are conspicuous at primary minimum, or if the macroscopic motions in the circulatory system of gas around the two components are appreciable. The former alternative may be disregarded since the profiles do not suggest any self-reversal effects. An interesting feature is the development of intense violet edges immediately after the primary and secondary minima. All the Heii lines develop such a violet edge and this pattern is followed by the Hei lines at XX5875 and 4471. It is difficult to observe this effect in the violet wing of ~656o since the io~a-F emulsion used has a dip in sensitivity in this wave-length region. HD 193576. Well-widened spectra in the blue region for this star have been used in the determination of equivalent widths for Heii 4860, Heii 4686, Nv 4603 and Niv 4058. When plotted with phase the lines Heii 4686 and Niv 4058 have negligible eclipse effects at primary minimum. Heii 4860 and Nv 4603 have minimum intensities at primary minimum, in the latter case probably caused by its own intense violet edge coupled with the violet edge of ~46I9 of Nv. HD 193928. Large scale variations in the emission-line intensities of the violet edges of Hei 4471 and Nv 4603 are easily noticeable. At certain phases X4860 as well as Heii 4686 develop humps on the long wave-length side of the profile. In the case of HD 214419 we find that the increase in brightness at primary and secondary minima is shared by all the emission lines measured. In HD 193576, Heii 4860 and Nv 4603 do not share the behavior of Heii 4686 and Nvi 4058. It would be of great interest to obtain photoelectric light curves of this star in the light of Heii 3206 and Niv 3483. One of us (Bappu 1951) has suggested that the increase in intensity of the emission lines in HD 214419 could be explained on the basis of a common envelope model. Such a situation would demand that the abnormal behavior be shared by all the emission lines together, a phenomenon that we have found to exist in HD 214419. The validity of the common-envelope hypothesis would cease to exist in those systems that are not close binaries. Verification of this hypothesis might therefore be made by carrying out programs of emission line photometry in WolfRayet binary systems having different periods. Bappu, M. K. V. 1951, Harvard thesis. Hiltner, W. A. 1950, Ap. J. 112, 447. U. P. Government Astronomical Observatory, Banaras, India. Title: Emission-Line Profiles from Expanding Envelopes. Authors: Vainu Bappu, M. K.; Menzel, D. H. Bibcode: 1954ApJ...119..508V Altcode: We have developed a method for calculating the emission4ine profiles from an expanding envelope. The method applies to an envelope where the emission intensity varies with latitude. Some typically illustrative cases are considered. Title: Magnitudes and colours of some members of the Perseus Cluster Authors: Vainu Bappu, M. K. Bibcode: 1954MNRAS.114..687V Altcode: 1954MNRAS.114..687B No abstract at ADS Title: A photoelectric study of early-type supergiants around h and χ Persei Authors: Bappu, M. K. Vainu Bibcode: 1954MNRAS.114..680B Altcode: Photoelectric colours and magnitudes for thirty early-type stars, classified as supergiants belonging to the double cluster in Perseus, have been determined with the aid of the Lick 1 -inch refractor. Measures of four stars in Harvard Standard Region Ciz were used for the tie-in to the (P, V) system. A general increase of absorption is found as one passes from h to Persei, in accordance with the earlier conclusions of Miss Pismis. A considerable non-uniformity of interstellar absorption exists around the cluster. The supergiants of type Bz and the Bo, Bo , Bi and Bz stars of luminosity class III yield a distance modulus of 11m.7 for the cluster of supergiants, corresponding to a distance of z z kps. Using the new value of the distance modulus, absolute magnitudes have been calculated for supergiants of other spectral classes. The number of stars used in this investigation is too few to give an estimate of the dispersion in Mv for these early-type supergiants. Title: The variation of emission-line intensities in CQ Cephei. Authors: Bappu, M. K. Vainu Bibcode: 1952AJ.....57....6B Altcode: The binary nature of the NJolf Rayet star HD 214419 was first noted by McLaughlin and Hiltner,' at Michigan in 1941. Shortly thereafter Gaposchkin2 showed the star to be an eclipsing system with two well-defined minima. Hiltner3 recently studied the system photoelectrically and obtained light-curves in the ultraviolet and yellow regions of the spectrum as well as a light curve of the emission line 4686A of Heii. The variation of 4686 differed from that of the integrated case in that it had maxima at conjunctions and minima at elongations, or in other words the geometry of the system is such that 4686 is most intense when either star is eclipsed. To determine whether other lines of Heii and * Of papers presented at the Eighty-sixth Meeting of the American Astronomical Society, East Cleveland, Ohio, December 26-29, 1951. those of nitrogen have a variation with phase similar to that of 4686A, spectra were taken throughout the 1.64 day period and central intensities, corrected for the eclipse of the continuum, determined. The Heii lines X4861, X4542, X4026, were eclipsed at both primary and secondary minima, with the intensity of emission outside eclipse immediately after primary minimum, lower than the intensity at third quadrature. The lines of nitrogen, Niii 4528, Niv 4058, Nv 4603, have a variation with phase similar to Heii 4861, but the intensity at first quadrature is greater than at third quadrature. There is slight evidence that the depths of primary minima are different for NIlI, Niv and. Nv, in that Nv has the smallest depth and Niii the largest, but the material analyzed so far is very little to establish this definitely. Hoěver, if this is real, it shows that Nv is less eclipsed compared to the NIlI zone. From geometrical considerations, it is possible that Nv is present in a higher layer of the atmosphere than Niii, or in other words a positive excitation gradient is present in the atmosphere. The presence of a secondary minimum in the light curves of HIl 4861, Niv 4058 and other lines of nitrogen indicates that a fair contribution to the overall emission comes from a region in between the two stars. The differences between the intensities at first and third quadratures may be explained as due to the asymmetric distribution of the emission. If one assumes that the system of GQ Cephei is a very close binary with a common envelope in which 4686A is excited, the light curve can be explained as due to the changes in the degree of occultation of this emission envelope. In such a picture more of the envelope is occulted at first and third quadratures than at times of primary and secondary minima. But as the other Heii lines are not present so far out from the center of mass of the system, it is possible that a fluoresence mech nism involving Lyman a, as Bowen4 has suggested, is responsible for the excitation of 4686A. If so the light-curve of Heii 3203 should be identical to those of Heii 4861, and Niv 4058, and hence a study of its variation in this eclipsing system would be valuable. I.Pub. A.S.P. 53, 328, 1941. 2. Ap. J. 100, 242, 1944. 3. Ap. J. 112, 477, 1950. 4. Ap. J. 8 , 1, 1935. Iount Wilson and Palomar Observatories, Pasadena, Calff. Title: The Problem of Wolf-Rayet Atmospheres. Authors: Bappu, Manali K. V. Bibcode: 1952PhDT.........1B Altcode: No abstract at ADS Title: The Nature of Comets Authors: Vainu Bappu, M. K. Bibcode: 1952ASPL....6..229V Altcode: 1952ASPL..279.....V No abstract at ADS Title: A spectroscopic study of Wolf-Rayet stars. Authors: Bappu, M. K. V. Bibcode: 1951AJ.....56..120B Altcode: No abstract at ADS Title: On the Light Curves of RX Librae and TV Canis Majoris Authors: Bappu, M. K. Vainu Bibcode: 1951BHarO.920...10B Altcode: No abstract at ADS Title: A spectroscopic study of Wolf-Rayet stars. Authors: Bappu, M. K. Vainu Bibcode: 1951AJ.....56R.120B Altcode: A study has been made of the profiles and total intensities of the emission lines of seven bright Wolf-Rayet stars in Cygnus, three of which belong to the carbon sequence and the rest to the nitrogen sequence. The well known eclipsing binary CQ Cephei was also included on the program, and the variations in the profiles of the emission lines and their total intensities during a cycle investigated. The broad emission band X4058, tentatively identified as due to Niv, has been found to be split into three components with wave lengths of 4044, 4057, and 4066 A. The lines X4044 and X4066 have been tentatively identified as due to Nii and Ciii, respectively. The line X4066 Ciii is moderately strong in carbon stars and as carbon lines have been found in nitrogen stars this identification is probably correct. The flat-topped nature of X4058, as shown by Beals to exist in BD 3504001, can then be explained as due to the *Of papers presented at the Eighty-fifth Meeting of the American Astronomical Society, Washington, D. C., J'ine 20-23, 1951. blending by physical causes of these components. The line ~5696 in carbon stars, identified as due to Ciii, has been observed to have a short wavelength component, X568 I, which has been tentatively identified with the 3s1P0-3P1D transition of Nii. If such an identification is correct, one would expect the transition 3S3PO~3p3P, X4630, to be observable and of medium intensity. The observation of this line is difficult because of the violet-absorption edge of X4650 due to Ciii. Nevertheless, the line has `been detected in BD 3504013. The occurrence of central reversals in WolfRayet stars is a rare phenomenon. The spectrograms of BD 3504001 reveal a deep core for ~4686 Heii, and a faint one for X54I I Heii. These might be central reversals or they may possibly be due to a non-uniform distribution of the emission on the stellar surface. Intrinsic variations of the spectral lines, as has been shown by Struve' to exist in HD 151932, have been found in two stars of the nitrogen sequence, BD 3703821 and BD 3504(>()I. The emission line X4603 Nv and its violet-edge experience changes in intensity. The line X4640 of Niii, and the Niii lines blended with N4542 Heii as well as ~447I Hei also show marked fluctuations. In the case of the eclipsing variable CQ Cephei, the profile of ~4686 Heii has been determined at different phases. While changes in form and intensity are immediately apparent, no marked asymmetry, as has been found by Beals2 for lIOL in V444 Cygni, has been found here. The intensities of the band X4640 have a curve of variation with phase, similar to the N4686 light curve derived recently by Hiltner.1 The line N4058 Niv has marked violet absorption edges at both primary and secondary minima. The changes in intensity of X4542 and X447 I are similar to those found by Mu~nch4 in V444 Cygni. I.Ap. J. 100, 198, 1944. 2.M. N. 104, 205, 1944. 3.Ap. J. 112, 477, 1950. 4.Ap. J. 112, 266, 1950. Harvard College Observatory, Cambridge, Mass. Title: The Spectrum of the Light of the Night Sky during the Recent Sunspot Maximum. Authors: Vainu Bappu, M. K. Bibcode: 1950ApJ...111..201V Altcode: 1950HarRe.336....1B No abstract at ADS