Astronomy:HD 151804
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 16h 51m 33.72181s[2] |
| Declination | −41° 13′ 49.9195″[2] |
| Apparent magnitude (V) | 5.22 - 5.28[3] |
| Characteristics | |
| Spectral type | O8 Iaf[4] |
| U−B color index | −0.838±0.039[5] |
| B−V color index | 0.066±0.013[5] |
| Variable type | α Cygni[3] |
| Astrometry | |
| Radial velocity (Rv) | −63±4[6] km/s |
| Proper motion (μ) | RA: −0.693±0.125[2] mas/yr Dec.: −0.754±0.105[2] mas/yr |
| Parallax (π) | 0.4893 ± 0.1180[2] mas |
| Distance | approx. 7,000 ly (approx. 2,000 pc) |
| Absolute magnitude (MV) | −7.3[7] |
| Details | |
| Mass | 40±5[8] M☉ |
| Radius | 35.4±1.2[8] R☉ |
| Luminosity | 800000+500000 −300000[8] L☉ |
| Surface gravity (log g) | 3.0±0.2[8] cgs |
| Temperature | 29000±500[8] K |
| Rotational velocity (v sin i) | 104±14[9] km/s |
| Age | 2.1[10] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 151804, also known as HR 6245 and V973 Scorpii, is a blue supergiant star about 7000 light years from the Earth, in the constellation Scorpius.[2] It is a 5th magnitude star, so it will be faintly visible to the naked eye of an observer far from city lights. It is a variable star, whose brightness varies slightly from magnitude 5.22 to 5.28, on time scales of a few days.[3][12] It is one of the brightest stars in the Scorpius OB1 association,[7] and is located half a degree from NGC 6231,[13] which is part of the same association.
HD 151804 was determined to be a Wolf-Rayet star sometime between 1888 and 1894 at the Harvard College Observatory.[14] More modern publications classify it as an Of star, however.[15]
Photometric observations published by Bart Bok et al. in 1966[16] and Nancy Morrison in 1975[17] indicated than HD 151804 might be a variable star. Variability was confirmed by Arnout van Genderen et al. in 1989. They could not deduce a period, but noted that it varied on a timescale of less than two days.[18] In 1990, HD 151804 was given the variable star designation V973 Scorpii.[19]
Tahina Ramiaramanantsoa et al. studied HD 151804 in 2015, using the BRITE constellation of nanosatellites. During their two-month period of high cadence observations, they found that the star's brightness varied by 0.04 magnitudes, showing a superposition of a large number of periods, the most pronounced of which were less than one day. These different pulsation modes had lifetimes of five to ten days. They argue that these pulsations may be gravity waves, stochastically excited by the star's convective core.[20]
In 1968, John Hutchings discovered that HD 151804 has a stellar wind.[13] It is losing mass at a rate of 6×10−6M☉ per year. The wind's terminal velocity is 1450 km/sec.[8][21]
References
- ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 3.0 3.1 3.2 Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports 61 (1): 80. doi:10.1134/S1063772917010085. Bibcode: 2017ARep...61...80S.
- ↑ Sota, A.; Apellániz, J. Maíz; Morrell, N. I.; Barbá, R. H.; Walborn, N. R.; Gamen, R. C.; Arias, J. I.; Alfaro, E. J. (March 2014). "The Galactic O-Star Spectroscopic Survey (GOSSS). II. Bright Southern Stars". The Astrophysical Journal Supplement 211 (1): 10. doi:10.1088/0067-0049/211/1/10. Bibcode: 2014ApJS..211...10S.
- ↑ 5.0 5.1 Maíz-Apellániz, Jesús; Walborn, Nolan R.; Galué, Héctor Á.; Wei, Lisa H. (March 2004). "A Galactic O Star Catalog". The Astrophysical Journal Supplement Series 151 (1): 103–148. doi:10.1086/381380. Bibcode: 2004ApJS..151..103M.
- ↑ Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. Bibcode: 2006AstL...32..759G.
- ↑ 7.0 7.1 Humphreys, R. M. (December 1978). "Studies of luminous stars in nearby galaxies. I. Supergiants and O stars in the Milky Way". Astrophysical Journal Supplement Series 38: 309–350. doi:10.1086/190559. Bibcode: 1978ApJS...38..309H.
- ↑ 8.0 8.1 8.2 8.3 8.4 8.5 Crowther, P. A.; Evans, C. J. (September 2009). "A FEROS spectroscopic study of the extreme O supergiant He 3-759". Astronomy and Astrophysics 503 (3): 985–990. doi:10.1051/0004-6361/200912631. Bibcode: 2009A&A...503..985C.
- ↑ Howarth, Ian D.; Siebert, Kaj W.; Hussain, Gaitee A. J.; Prinja, Raman K. (January 1997). "Cross-correlation characteristics of OB stars from IUE spectroscopy". Monthly Notices of the Royal Astronomical Society 284 (2): 265–285. doi:10.1093/mnras/284.2.265. Bibcode: 1997MNRAS.284..265H.
- ↑ Petit, V.; Wade, G. A.; Schneider, F. R. N.; Fossati, L.; Kamp, K.; Neiner, C.; David-Uraz, A.; Alecian, E. et al. (November 2019). "The MiMeS survey of magnetism in massive stars: magnetic properties of the O-type star population". Monthly Notices of the Royal Astronomical Society 489 (4): 5669–5687. doi:10.1093/mnras/stz2469. Bibcode: 2019MNRAS.489.5669P.
- ↑ "HD 151804 -- Blue Supergiant". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+151804+--+Blue+Supergiant.
- ↑ Prinja, R. K.; Fullerton, A. W.; Crowther, P. A. (July 1996). "Variability in the optical wind lines of HD 151804 (O8 Iaf)". Astronomy and Astrophysics 311: 264–272. Bibcode: 1996A&A...311..264P.
- ↑ 13.0 13.1 Hutchings, J. B. (1968). "Expanding atmospheres in OB supergiants-I". Monthly Notices of the Royal Astronomical Society 141 (2): 219–249. doi:10.1093/mnras/141.2.219. Bibcode: 1968MNRAS.141..219H.
- ↑ Campbell, W. W. (1894). "The Wolf-Rayet stars". Astronomy and Astro-Physics 13: 448–476. Bibcode: 1894AstAp..13..448C. https://archive.org/details/sim_astronomy-and-astro-physics_1894-06_13_7/page/448/mode/2up. Retrieved 8 March 2023.
- ↑ Smith, Lindsey F. (1968). "Absolute magnitudes and intrinsic colours of Wolf-Rayet stars". Monthly Notices of the Royal Astronomical Society 140 (4): 409–433. doi:10.1093/mnras/140.4.409.
- ↑ Bok, B. J.; Bok, P. F.; Graham, J. A. (1966). "A photometric study of the I Scorpii association". Monthly Notices of the Royal Astronomical Society 131 (2): 247–252. doi:10.1093/mnras/131.2.247. Bibcode: 1966MNRAS.131..247B.
- ↑ Morrison, N. D. (August 1975). "Photometry of O-type stars, interpreted with reference to model atmospheres". Astrophysical Journal 200: 113–121. doi:10.1086/153767. Bibcode: 1975ApJ...200..113M.
- ↑ van Genderen, A. M.; Bovenschen, H.; Engelsman, E. C.; Goudfrooy, P.; van Haarlem, M. P.; Hartmann, D.; Latour, H. J.; Ng, Y. K. et al. (August 1989). "Light variations of massive stars (alpha Cygni variables). IX". Astronomy and Astrophysics Supplement Series 79: 263–282. Bibcode: 1989A&AS...79..263V.
- ↑ Kazarovets, E. V.; Samus, N. N. (October 1990). "The 70th Name-List of Variable Stars". Information Bulletin on Variable Stars 3530: 1. Bibcode: 1990IBVS.3530....1K. https://ibvs.konkoly.hu/pub/ibvs/3501/3530.pdf. Retrieved 8 March 2023.
- ↑ Ramiaramanantsoa, Tahina; Ratnasingam, Rathish; Shenar, Tomer; Moffat, Anthony F. J.; Rogers, Tamara M.; Popowicz, Adam; Kuschnig, Rainer; Pigulski, Andrzej et al. (October 2018). "A BRITE view on the massive O-type supergiant V973 Scorpii: hints towards internal gravity waves or sub-surface convection zones". Monthly Notices of the Royal Astronomical Society 480 (1): 972–986. doi:10.1093/mnras/sty1897. Bibcode: 2018MNRAS.480..972R.
- ↑ Rubio-Díez, M. M.; Sundqvist, J. O.; Najarro, F.; Traficante, A.; Puls, J.; Calzoletti, L.; Figer, D. (February 2022). "Upper mass-loss limits and clumping in the intermediate and outer wind regions of OB stars". Astronomy and Astrophysics 658: A61. doi:10.1051/0004-6361/202040116. Bibcode: 2022A&A...658A..61R.
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