HD 316285 was identified in 1925 as an unusual star havingP Cygni lines in its spectrum, lines with both emission and absorption components offset by a doppler shift.[8] It was classified as aBe star although it is now known to be a supergiant and the class of Be stars excludes supergiants,[9] and was included in the Mount Wilson Observatory catalogue of B and A stars with bright lines of hydrogen (MWC) as entry 272.[10] In 1956, it was reported that the emission was due to an expanding atmosphere rather than the circumstellar discs of less evolved Be stars.[11] In 1972 it was discovered to have aninfrared excess, an unusually high emission at infrared wavelengths due to surrounding warm dust.[12]
In 1961, HD 316285 was catalogued as planetary nebula Bl3-11,[13] although that classification was quickly cast into doubt.[14][15]
The spectrum shows that HD 316285 has only 1.5 times as much hydrogen as helium and elevated levels of carbon, nitrogen, and oxygen, so it can be identified as a highly evolved star. It has been calculated to be losing mass at the rate ofM☉ every four thousand years via itsstellar wind.[5]
Gaiaastrometry suggests a distance much larger than the accepted 1.9kpc,[20][1] and would imply a much higher luminosity. It may even lie close to theGalactic Center.[21]
HD 316285 has been identified as a possible type II-b or type IInsupernova candidate in modelling of the fate of stars 20 to 25 times the mass of the Sun. It has been shown that these supernovae may explode directly from stars in an LBV phase after spending time as ared supergiant.[22]
A possible companion has been reported on the basis of a helical outflow of material apparently originating from HD 316285. This would be caused by a jet being twisted into a spiral shape by orbital motion.[23]
^abcDucati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system".CDS/ADC Collection of Electronic Catalogues.2237: 0.Bibcode:2002yCat.2237....0D.
^Lopes, D. F.; Damineli Neto, A.; De Freitas Pacheco, J. A. (1992). "A spectroscopic study of luminous peculiar B-type stars".Astronomy and Astrophysics.261: 482.Bibcode:1992A&A...261..482L.
^abcHillier, D. J.; Crowther, P. A.; Najarro, F.; Fullerton, A. W. (1998). "An optical and near-IR spectroscopic study of the extreme P Cygni-type supergiant HDE 316285".Astronomy & Astrophysics.340:483–96.Bibcode:1998A&A...340..483H.
^abcAnders, F.; Khalatyan, A.; Queiroz, A. B. A.; Chiappini, C.; Ardevol, J.; Casamiquela, L.; Figueras, F.; Jimenez-Arranz, O.; Jordi, C.; Monguio, M.; Romero-Gomez, M.; Altamirano, D.; Antoja, T.; Assaad, R.; Cantat-Gaudin, T.; Castro-Ginard, A.; Enke, H.; Girardi, L.; Guiglion, G.; Khan, S.; Luri, X.; Miglio, A.; Minchev, I.; Ramos, P.; Santiago, B. X.; Steinmetz, M. (2022). "VizieR Online Data Catalog: StarHorse2, Gaia EDR3 photo-astrometric distances (Anders+, 2022)".Vizier Online Data Catalog.Bibcode:2022yCat.1354....0A.
^Blanco, V. M. (1961). "A catalogue of Half emission objects in the galactic center region".Contr. From the Bosscha Observ. Lembang.13: 1.Bibcode:1961CoBos..13....1B.
^Vorontsov-Veliaminov, B. A.; Kostiakova, E. B.; Dokuchaeva, O. D.; Arkhipova, V. P. (1975). "Planetary nebulae near the galactic center".Soviet Astronomy.19: 163.Bibcode:1975SvA....19..163V.
^Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)".VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S.1.Bibcode:2009yCat....102025S.
^Watson, C. L. (2006). "The International Variable Star Index (VSX)".The Society for Astronomical Sciences 25th Annual Symposium on Telescope Science. Held May 23–25.25: 47.Bibcode:2006SASS...25...47W.
