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HD 144941 is an extreme He (EHe) star, a rare class of subdwarf OB star formed from the merger of two white dwarf (WD) stars. Uniquely amongst EHe stars, its light curve has been reported to be modulated entirely by rotation, suggesting the…

Solar and Stellar Astrophysics · Physics 2021-08-04 M. E. Shultz , O. Kochukhov , J. Labadie-Bartz , A. David-Uraz , S. P. Owocki

In this paper we present high resolution 4.7micron spectra of the isolated Herbig Be star HD100546. HD100546 has been the subject of intense scrutiny because it is a young nearby star with a transitional disk. We observe the Delta v=1…

Solar and Stellar Astrophysics · Physics 2009-08-11 Sean D. Brittain , Joan R. Najita , John S. Carr

Coude spectroscopic data of a poorly-studied peculiar supergiant, HD327083, are presented. Halpha and Hbeta line profiles have been fitted employing a non-LTE code adequate for spherically expanding atmospheres. Line fits lead to estimates…

Astrophysics · Physics 2009-11-06 M. A. D. Machado , F. X. de Araujo , S. Lorenz-Martins

In this Letter, we shed light on the evolutionary phase of HD 144812, a Galactic yellow supergiant showing infrared excess that is typically expected for evolved stars undergoing enhanced mass-loss activity. We present high-resolution…

Solar and Stellar Astrophysics · Physics 2025-03-27 Michalis Kourniotis , Michaela Kraus , Maria Laura Arias , Lydia S. Cidale

{We aim to detect and interpret photometric and spectroscopic variability of the bright CoRoT B-type supergiant target HD\,46769 ($V=5.79$). We also attempt to detect a magnetic field in the target.} {We analyse a 23-day oversampled CoRoT…

We present new Far Ultraviolet Spectroscopic Explorer (FUSE) observations of Mira A's wind-accreting companion star, Mira B. We find that the strongest lines in the FUSE spectrum are H2 lines fluoresced by H I Lyman-alpha. A previously…

Astrophysics · Physics 2009-11-10 Brian E. Wood , Margarita Karovska

We present Balmer lines spectroscopy for a sample of 48 Be stars. For most of them, H$\alpha$ and H$\beta$ have been observed more than two times, in a total period spanning almost two years between 2008 and 2009. Spectral synthesis of the…

Solar and Stellar Astrophysics · Physics 2015-06-12 G. Catanzaro

We obtained 7 spectra of the Be star V423 Aur on Dec. 5th, 2017 using the LAMOST Medium-Resolution Spectrograph with exposures from 600 to 1200 seconds. These spectra show the irregular H{\alpha} emission line profile variations (LPVs). In…

Solar and Stellar Astrophysics · Physics 2020-04-15 Chao-Jian Wu , Hong Wu , Chih-Hao Hsia , Wei Zhang , Juan-Juan Ren , Guang-Wei Li , Jian-Jun Chen , Fan Yang , Jian-Rong Shi , Yong-Hui Hou , Ji-Feng Liu

We investigate the spectral characteristics of the Be/X-ray binary system, EXO 051910+3737.7, in which Be/X-ray systems are the largest sub-class of high-mass X-ray binaries. Spectroscopic observations are taken by the Thai National…

The nebular He II {\lambda}1640 emission line is observed in star forming galaxies out to large distances and can be used to constrain the properties of sources of He+ ionizing photons. For this purpose, it is crucial to understand which…

Astrophysics of Galaxies · Physics 2023-03-09 Andres Sixtos , Aida Wofford , Andreas A. C. Sanders , Antonio Peimbert

We aim to investigate the origin of the HI Br$\gamma$ emission in young stars by using GRAVITY to image the innermost region of circumstellar disks, where important physical processes such as accretion and winds occur. With high spectral…

We present the first detections of gas around a 2.1 Myr old debris disc-bearing intermediate-mass star, HD 44892. Gas is detected both in $^{12}$CO (2-1) emission through ALMA Band 6 observations and in absorption in Ca II K and H, seen…

Earth and Planetary Astrophysics · Physics 2025-12-24 Karolina M. Szewczyk , Olja Panić , Daniela P. Iglesias , Tim D. Pearce , James M. Miley

Time series spectrophotometry of the L5 dwarf 2MASS 01443536-0716142 showed strong H\alpha emission which declined by nearly 75% in four consecutive exposures. The line was not detected in emission on a spectrum obtained eleven months…

High-quality K-band spectra of strongly reddened point sources, deeply embedded in (ultra-) compact HII regions, have revealed a population of 20 young massive stars showing no photospheric absorption lines, but sometimes strong Br-gamma…

Astrophysics · Physics 2009-11-11 A. Bik , L. Kaper , L. B. F. M. Waters

We report the results of spectroscopic and photometric observations of the emission-line object AS 386. For the first time, we found that it exhibits the B[e] phenomenon and fits the definition of an FS CMa type object. The optical spectrum…

Delta Sct - gamma Dor hybrids pulsate simultaneously in p- and g-modes, which carry information on the structure of the envelope as well as to the core. Hence they are key objects for investigating A and F type stars with asteroseismic…

Solar and Stellar Astrophysics · Physics 2015-05-30 M. Hareter , L. Fossati , W. Weiss , J. C. Suárez , K. Uytterhoeven , M. Rainer , E. Poretti

In this paper we report on the real nature of the star HD 145792, classified as He weak in {\it ``The General Catalogue of Ap and Am stars''}. By means of [email protected] high resolution spectroscopic data, we refined the atmospheric…

Astrophysics · Physics 2009-11-13 G. Catanzaro

We report the second study from the FUSE survey of molecular hydrogen in translucent clouds, for the line of sight toward HD 110432. This star lies beyond the Coalsack dark nebula, and with E(B-V) = 0.40, and A_V = 1.32 this line of sight…

We present a sample of 2865 emission line galaxies with strong nebular He II 4686 emissions in Sloan Digital Sky Survey Data Release 7 and use this sample to investigate the origin of this line in star-forming galaxies. We show that…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Maryam Shirazi , Jarle Brinchmann

LHA 115-S 18 is a very peculiar emission-line star exhibiting the B[e] phenomenon. Located in the Small Magellanic Cloud, its spectrum shows features of an extremely wide range of excitation and ionization stages, extending from highly…

Solar and Stellar Astrophysics · Physics 2015-06-11 A. F. Torres , M. Kraus , L. S. Cidale , R. Barbá , M. Borges Fernandes , E. Brandi