HD 37836 explained

HD 37836 is a candidate luminous blue variable located in the Large Magellanic Cloud and one of the brightest stars in its galaxy.^{[1] [2]}

History

The star was first mentioned in a 1901 paper as an object with an unusual spectrum with bright H-alpha, H-beta and H-delta lines located in the LMC.^[3] Later it was catalogued in the Henry Draper Catalogue and given the designation HD 37836. In 1957 it was noted that its spectral lines show a P Cygni profile.^[4]

Stellar properties

HD 37836 is an extremely luminous blue supergiant with parameters similar to other similar stars, such as η Carinae A. It is also an α Cygni variable.^[5] Its apparent magnitude varies by ~0.2 magnitudes.

In 1983, its luminosity was estimated to be and its mass was estimated to be 100, which would make it one of the most luminous and most massive known stars.^[6]

A paper published in 1987 again noted the star's peculiar spectrum. It also concluded that the star might be similar to HD 269445 and Hen S 131. The star's luminosity was estimated to be around .^[7]

A year later, it was classified as a possible S Doradus variable.^[8] A 1998 paper considers it an active LBV, an Alpha Cygni variable, and a 2018 census of LBVs considers it to be a candidate.^[9]

A 2023 paper estimates its luminosity to be 4.2 million solar luminosities and its temperature to be 28,200 K based on the star's spectral type, corresponding to a radius of 85 solar radii, comparable to that of Rigel.^[10]

References

1. Lennon . Daniel J. . Marel . Roeland P. van der . Lerate . Mercedes Ramos . O’Mullane . William . Sahlmann . Johannes . 2017-07-01 . Gaia TGAS search for Large Magellanic Cloud runaway supergiant stars - Candidate hypervelocity star discovery and the nature of R 71 . Astronomy & Astrophysics . en . 603 . A75 . 10.1051/0004-6361/201630076 . 1611.05504 . 2017A&A...603A..75L . 119474184 . 0004-6361.
2. Richardson . Noel D. . Mehner . Andrea . 2018-07-11 . The 2018 Census of Luminous Blue Variables in the Local Group . Research Notes of the AAS . 2 . 3 . 121 . 10.3847/2515-5172/aad1f3 . 1807.04262 . 2018RNAAS...2..121R . 2515-5172 . free .
3. Pickering . E. C. . Fleming . W. P. . 1901-09-01 . Objects having peculiar spectra . The Astrophysical Journal . 14 . 144–146 . 10.1086/140844 . 1901ApJ....14..144P . 0004-637X.
4. Smith . Henry J. . Spectra of Bright-Line Stars in the Large Magellanic Cloud . 1957-04-01 . Publications of the Astronomical Society of the Pacific . en . 69 . 407 . 137 . 10.1086/127032 . 1957PASP...69..137S . 122612430 . 1538-3873. free .
5. Balona . L A . Handler . G . Chowdhury . S . Ozuyar . D . Engelbrecht . C A . Mirouh . G M . Wade . G A . David-Uraz . A . Cantiello . M . 2019-05-21 . Rotational modulation in TESS B stars . Monthly Notices of the Royal Astronomical Society . en . 485 . 3 . 3457–3469 . 10.1093/mnras/stz586 . 0035-8711. free . 1902.09470 .
6. van Genderen . A. M. . Groot . M. . The . P. S. . 1983-01-01 . On the photometric differences between luminous OBA type stars in the LMC with and without P Cygni characteristics . Astronomy and Astrophysics . 117 . 53–59 . 1983A&A...117...53V . 0004-6361.
7. Stahl . O. . Wolf . B. . 1987-07-01 . The peculiar emission-line supergiant HD 37836 . Astronomy and Astrophysics . 181 . 293–299 . 1987A&A...181..293S . 0004-6361.
8. Lortet . M. C. . 1988-12-01 . A provisory catalogue of S-Dor candidate stars in the Magellanic Clouds . Bulletin d'Information du Centre de Donnees Stellaires . 35 . 145–154 . 1988BICDS..35..145L . 1169-8837.
9. van Genderen . A. M. . Sterken . C. . de Groot . M. . Reijns . R. A. . 1998-04-01 . Light variations of massive stars (alpha Cyg variables). XV. The LMC supergiants R99 (LBV), R103, R123 (LBV) and R128 . Astronomy and Astrophysics . 332 . 857–866 . 1998A&A...332..857V . 0004-6361.
10. Martin . John C. . Humphreys . Roberta M. . 2023-10-30 . A Census of the Most Luminous Stars. I. The Upper HR Diagram for the Large Magellanic Cloud . The Astronomical Journal . 166 . 5 . 214 . 10.3847/1538-3881/ad011e . 2023AJ....166..214M . 0004-6256 . free .