J/PAZh/32/48        UBV photometry of HD 331319              (Arkhipova+, 2006)

Study of the IR-Excess Supergiant HD 331319. Arkhipova V.P., Ikonnikova N.P., Komissarova G.V., Esipov V.F. <Pis'ma Astron. Zh. 32, 48 (2006)> =2006PAZh...32...48A 2006PAZh...32...48A =2006AstL...32...45A 2006AstL...32...45A
ADC_Keywords: Stars, supergiant - Photometry, UBV Keywords: post-AGB supergiants - photometric and spectroscopic observations - photometric variability Abstract: We report the discovery of brightness variability in the IR-excess early F supergiant HD 331319, a candidate post-AGB star. Over three years of systematic UBV observations, the star showed low-amplitude (up to 0.17m in V) quasi-periodic brightness variations on a time scale of 45 days. A preliminary analysis of our photometry indicates that HD 331319 and other typical post-AGBF supergiants have a similar pattern of variability. A study of the extinction toward HD 331319 leads us to conclude that the fraction of the circumstellar extinction is small for this star. We present low-resolution spectroscopy for HD 331319 and discuss the spectral classification of post-AGB F supergiants using HD 331319, HD 161796, HD 187885, and HD 56126 as examples. Description: We began our UBV observations of HD 331319 in 2002. From June 2002 through April 2005, we obtained 104 magnitude estimates for the star with a photoelectric photometer attached to a 60cm Zeiss-600 telescope at the Crimean Station of the Strenberg Astronomical Institute. Objects: ------------------------------------------------------------------- RA (2000) DE Designation(s) ------------------------------------------------------------------- 19 49 29.5 +31 27 16 HD 331319 = IRAS 19475+3119 = PN PM 2-42 ------------------------------------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 40 132 UBV observations of HD 331319 -------------------------------------------------------------------------------- Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 7 I7 d JD Julian date 9- 13 F5.3 mag Umag U magnitude 15- 20 F6.3 mag Bmag B magnitude 22- 27 F6.3 mag Vmag V magnitude 29- 33 F5.3 mag U-B U-B color index 35- 39 F5.3 mag B-V B-V color index --------------------------------------------------------------------------------
(End) Veta Avedisova [INASAN] 13-Apr-2006
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