2338 PHYS:CS (GENERAL) Astrophysics and Cosmology 23546 EXPLORATION OF TRE UNIVERSE, SECOND ELfTION, Abell, George. New York; Holt, Rinchart, and Winston (1989, 739. This book is designed for s one~ or two-semester Course an an (ntroduction to astranomy and astrophysics No apectal training in ecience or matiematics is required for an understanding of the text The book ts Itberally illustrated tn black and white and some color. (W.D.M) Cosmic Ray Exposure Ages 23547 DATING OF METEORITES BY THE HIGH-TEMPFRATURE RELEASE OF IODINE-CORRELATED!Xe, Podosek, FLA. (Univ, of Caltfornia, Berkeley), Acta; 34: 341-65(Mar 1970}, Geochim. Coamochim, Correlations between the amounts of "Xe and "Xo released in atepwine heating of peutron-irradiated meteorites were uted to determine the initial ratio "1/"?) and hence 2 relative formation time for the various samples. The formation timea In millions of years fretative to the L4 chondrite Bjurbdle} of nine specimens are as follows -3 9 + 0.7 for Karoonda (C4 chondrite); 3.1 4 0.6 and 10.5 + 0 7 for the matrix and chondrules, respectively, of Chainpur (LL3), 7.5 ¢ 19 for St. Severin (L.L6); 3.942 9 and 23.410 for the matrix and chondrules, reapectively, of Allegan (45), 3.6 + 0.7 for Pefis Blanca Bpring and 20.8 ¢ 9.5 for Bishop- sille faubrites), 3.8 + 6.7 for a silicate inclusion of the fron me- teorite El Taco (Campo del Clelo) No aseumptione were made about the amount of "Xe in the trapped gas. The correlations for previously) published data were aleo recalculated in the same way, with no assumptions about trapped '*Xe. For a group of chondrites previously reported to be isochronous with a mean simultancity of 25 miflton years, the recalculation confirms this mezn simulta- neity, but significant differences in formation times are resolved, An iodine — xenon age of 53 + 9 million yeare (after Byurbole) was obtained from unpublished data for the achondrite Lafayette. The re‘iability of iodine - xenon ages of individual meteorites la considered; in particular, the ages of Bishopvilie und Lafayette are jess reliable than those of most other meteorites studied, cspeclally in view of the anomalous ages reported. The re:evance of iod:ne xenon dating to theories of nucleosynthesis, earty solar system chronology, and theories of meteorite parent-body forMation ts discussed (auth) (CK) Stars Reter also to abstracts 23762, 23976, 24435, and 24516. 23548 (S¥0-3962-2}) ANNUAL PROGRESS REPORT [ON AUCLEAR PHYSICS AND NUCLEOSYNTHESIS], {Cameron, ALG. W.) Science), CFsTt. (Yeshiva Univ,, New York. Belfer Graduate School of (17 Mar 1970], Contract AT(30-1)-3962, llp. Dep. Abreef summary is given on the work carried out in the areas of neutron-star matter, neutron-rich nuclei, the URCA process In white dwarte, end the nuclear mass formula, (W DM.) 23849 LIGHT VARIATION OF FOUR MAGNETIC VARIABLE STARS, van Genderen, A.M, (Leiden Observatory}. Astron. Astrophys,, Suppl, Ser.; 1: 123-7(Feb 1970), Photoelectric observations of the magnetic variable stars HD 8441, 2) Per, « Cas, and HD 25 384 are detailed. The first three stare were ohserved with a red filter only, the fourth one wan also observed In UAV (auth) 23350 PHOTOELECTRIC OBSERVATIONS OF 323 CYGNI. Sohansen, K sren T.; Rudkjocbing, J.; Gyldenkerne, K. (Univ, of Copenhagen Observatory, Brorfelde, Denmark}, Astron, Astron, Astrophye., Suppl, Ser.z 1: 149+64(Feb 1970). The tong pertod eclipeing binary 32 Cyg was observed at Copenhagen Unis eraity Observatory in Brorfeide during the 1959, 1967, and 1985 eclipses. The observations were made with UBV alandard {tere and several narrow-band filters, and the comhined light curve te disccesed A compartecn tx made with ress hrined ty other observers Atleast the 1965 eclipse ws 1 tat cet meat wee tw tital The atmospheric nature of the eclipes ie ote try the Fact that at a certain phase outside totality ‘. 4 fraction of the B ortar ractietion depends an the feafregton footatrvatden ‘auth 2308! PHOTOELECTRIC OBSERVATIONS OF EARLY A STARS, Johsnern, Karen T.; Gyidenkerne, K, (Univ. of Copene hagen Observatory, Brorielde, Denmark). Astron. Astrophys., Suppl, Ser.; i: 165-8 Feb 197, Photoelectric observations of the £ index and of indices atmilar to those af the Strdmgren uvby system were made for 437 Cald stars and for a number of stacs te the Coma Berenices, Praeaspe, NGC 6633, and NGC 1662 clusters, Of the field stars, 377 are AO— A2 atars north of dociination ~8° with V « 4.0; in the clustera mostly A stars were observed. The night-to-night correction method is described and the transformation of the observed indices to the uvby and § standard syatems js discussed in dotatl, auth) 7 23582 CATALOGUE OF PROPER MOTIONS FOR 487 A STARS, Olsen, Ht. J. Fogh (Univ. of Copenhagen Observatory, Brorfelde, Denmark), Astron, Astrophys, Suppl. Ser.; 2; 189- 97(Feb 1970). Proper motions and radial velocities are given for 437 A stars observed photoelectrically by Johansen and Gyidenkarne. Most of the proper motions are improved GC motions transformed to the FK4 systenr. (auth) 23883 NARROW-BAND PHOTOMETRYOF LATE-TYPE STARS, Heeggkvist, L.; Oje, T. (Uppsala Astronomical Observetory). Astron, Astrophys., Suppl. Ser.; 1: 199-232(Feh 2970). The distribution of stare in the direction perpendicular to the galactic plane {a investigated. It le limited to late-type stars, which are studfed by means of interference filters; the break at the G band and the cyanogen absorption are measured, The catalog includes al! late-type etars brighter than V = 5 north of declination —10° and those brighter than V = 4 north of galactic latitude + 60°. The relation between the two-dimensional classification establihed for the G and K stars and the MK classification la studied. It te shown that the giants and the dwarfs are wel! separated from each other and that the separation can be made complete ff the criteria ate complemented by the B-V color, It is also found that the M gianta can be classified quite accurately by ‘means of the same criteria The connection hetween the spectro- photometric criteria and the intringic colors In the UBV system 1a Investigated, and ft is found that different relations hold for the and the giants. The mean errors of typical B-V color e derived from the criterta and B—V are about +0 02 for the dwarfs and 49.03 to 40 03 for the giants. The absolute magnitudes of the late-type giants are discussed and a relation between the mean absolite magnitude in a volume of space and the epectrophotometric criteria is derived from astrometric data only (trigonometric parallaxea and proper motions in combination with radial velocities). The diapersion of the sbsciute magnitudes ls about 406. (auth) 23854 CASE B OF MASS EXCHANGE IN SYSTEMS 4+ 3.2Mo AND 441.6Mg. Harmanec, Petr (Astronomical Inst., Ondrejov, Czech.). Astrophys. Space Sct , 6: 497-503(Mar 1970) Two examples of caze A of masa exchange ure computed to estimate the effect of bagic initia! perameters on the course and the results of mase exchange. It seems that the resulting mass ~ of the original primary 19 independent of the initial mass ratio, the resulting orbital period 1a Independent of Initial mase of the primary, and surface hydragen content 1s independent of both of these parameters (auth) 23858 ONE EXAMPLE OF MASS EXCHANGE IN CASE AB Crech.) Astrophys Space Sel., 6: 492-6{Mar 1970) IN SYSTEM 5MQ + 4M>. Hora, J (Astronomical Inet , Ondrejov, Evolution af a binary system with masses of 5Mo end 4M, reapectively, and with orbital period of 1.41 days is studied by means of 'y model under of conservation of total masa and total orbital angular momentum of the system. Asa result of mase exchange between the components a binary with masees of 8.46 and 0.54 Mo is obtained Phyalcal parameters of the final product indicate possthle conthe end af mses exchange, (ath) 33856) DEVELOPMENT OF A COCOON STAR. Davideon, Kris (Corneil Untv., Ithaca, N. Y.). Astrophys. pace Sc1.; 6: 422-34(Mar 1970}, A beowly fortied masaive star le Likely to be surrounded by dense gas and dust sa {tt approaches the main sequence Radiation preseure must push some of the ianer material outward hefore