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HD 19993 and HD 29035: New bright A-type emission-line stars

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Anatoly S. Miroshnichenko, Associate Professor (Creator)
The University of North Carolina at Greensboro (UNCG )
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Abstract: We present the results of photometric and spectroscopic observations of two A-type stars (HD 19993 and HD 29035), optical counterparts of the IRAS sources (F03108+3729 and 04331+5211, respectively). Hα line emission is found in the optical spectra of both objects for the first time. Our analysis of the spectral line profiles and the photometric information shows that HD 19993 is an A7/8 II star (Teff ~ 7500 ± 200 K, log g = 2.7 ± 0.2, v sin i = 35 ± 2 km s-1, M = 4.8 ± 0.8 M⨀) with a mild metal deficit ([Fe/H] ~ -0.3 ± 0.1), while HD 29035 is a B9/A0 V star (Teff ~ 10 000 K, log g ~ 4, v sin i ~ 150 km s-1). The presence of an IR excess and the Hα emission in combination with a very different location in the Hertzsprung-Russell diagram suggest the different nature and evolutionary stages of the objects. We conclude that HD 29035 is a candidate Herbig Ae type star, a possible member of a group of similar objects. HD 19993 seems to be a post-main-sequence object.

Additional Information

Miroshnichenko, A.S., Kusakin, A.V., Bjorkman, K.S., Drake, N.A., Rudy, R.J., Lynch, D.K., Mazuk, S., Venturini, C.C., Puetter, R.C., Perry, R.B. 2003. A&A, 412, 219-228. HD 19993 and HD 29035: new bright A-type emission-line stars.
Language: English
Date: 2003
Techniques: spectroscopic, Techniques: photometric, Stars: circumstellar matter, Stars: individual: HD 19993, HD 29035