HD 151804

Last updated
HD 151804
V973ScoLightCurve.png
A light curve for V973 Scorpii, plotted from TESS data [1]
Observation data
Epoch J2000.0        Equinox J2000.0
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  mas [2]
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
V973 Sco, HR  6245, HIP  82493, SAO  227313 [11]
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 6×10−6 M☉ per year. The wind's terminal velocity is 1450 km/sec. [8] [21]

Related Research Articles

<span class="mw-page-title-main">Wolf–Rayet star</span> Heterogeneous stars with unusual spectra

Wolf–Rayet stars, often abbreviated as WR stars, are a rare heterogeneous set of stars with unusual spectra showing prominent broad emission lines of ionised helium and highly ionised nitrogen or carbon. The spectra indicate very high surface enhancement of heavy elements, depletion of hydrogen, and strong stellar winds. The surface temperatures of known Wolf–Rayet stars range from 20,000 K to around 210,000 K, hotter than almost all other kinds of stars. They were previously called W-type stars referring to their spectral classification.

<span class="mw-page-title-main">Luminous blue variable</span> Type of star that is luminous, blue, and variable in brightenss

Luminous blue variables (LBVs) are massive evolved stars that show unpredictable and sometimes dramatic variations in their spectra and brightness. They are also known as S Doradus variables after S Doradus, one of the brightest stars of the Large Magellanic Cloud. They are extraordinarily rare, with just 20 objects listed in the General Catalogue of Variable Stars as SDor, and a number of these are no longer considered LBVs.

<span class="mw-page-title-main">R136</span> Super star cluster in the constellation Dorado, in the Large Magellanic Cloud

R136 is the central concentration of stars in the NGC 2070 star cluster, which lies at the centre of the Tarantula Nebula in the Large Magellanic Cloud. When originally named it was an unresolved stellar object but is now known to include 72 class O and Wolf–Rayet stars within 5 parsecs of the centre of the cluster. The extreme number and concentration of young massive stars in this part of the LMC qualifies it as a starburst region.

<span class="mw-page-title-main">Westerlund 1</span> Super star cluster in the Milky Way Galaxy

Westerlund 1 is a compact young super star cluster about 3.8 kpc away from Earth. It is thought to be the most massive young star cluster in the Milky Way, and was discovered by Bengt Westerlund in 1961 but remained largely unstudied for many years due to high interstellar absorption in its direction. In the future, it will probably evolve into a globular cluster.

<span class="mw-page-title-main">Hypergiant</span> Rare star with tremendous luminosity and high rates of mass loss by stellar winds

A hypergiant (luminosity class 0 or Ia+) is a very rare type of star that has an extremely high luminosity, mass, size and mass loss because of its extreme stellar winds. The term hypergiant is defined as luminosity class 0 (zero) in the MKK system. However, this is rarely seen in literature or in published spectral classifications, except for specific well-defined groups such as the yellow hypergiants, RSG (red supergiants), or blue B(e) supergiants with emission spectra. More commonly, hypergiants are classed as Ia-0 or Ia+, but red supergiants are rarely assigned these spectral classifications. Astronomers are interested in these stars because they relate to understanding stellar evolution, especially star formation, stability, and their expected demise as supernovae.

<span class="mw-page-title-main">55 Cygni</span> Star in the constellation Cygnus

55 Cygni is a blue supergiant star in the constellation Cygnus. It is thought to be a member of the Cygnus OB7 stellar association at about 2,700 light years.

<span class="mw-page-title-main">WR 25</span> Binary star system in the constellation Carina

WR 25 is a binary star system in the turbulent star-forming region the Carina Nebula, about 6,800 light-years from Earth. It contains a Wolf-Rayet star and a hot luminous companion and is a member of the Trumpler 16 cluster. The name comes from the Catalogue of Galactic Wolf–Rayet Stars.

<span class="mw-page-title-main">V1073 Scorpii</span> Variable star in the constellation Scorpius

V1073 Scorpii is a variable star in the constellation Scorpius. It has a non-Greek Bayer designation of k Scorpii. The star has a blue-white hue and is visible to the naked eye with an apparent visual magnitude that fluctuates around +4.87. Parallax measurements yield a distance estimate of approximately 2,920 ly (896 pc) from the Sun, and it is drifting further away with a radial velocity of +7 km/s. It has an absolute magnitude of −6.8

<span class="mw-page-title-main">AH Scorpii</span> Star in the constellation Scorpius

AH Scorpii is a red supergiant variable star located in the constellation Scorpius. It is one of the largest stars known by radius and is also one of the most luminous red supergiant stars in the Milky Way.

R99 is a star in the Large Magellanic Cloud in the constellation Dorado. It is classified as a possible luminous blue variable and is one of the most luminous stars known.

<span class="mw-page-title-main">V915 Scorpii</span> Variable star in the constellation Scorpius

V915 Scorpii is an orange hypergiant variable star in the constellation Scorpius.

<span class="mw-page-title-main">V528 Carinae</span> Star in the constellation Carina

V528 Carinae is a variable star in the constellation Carina.

<span class="mw-page-title-main">WR 137</span> Star in the constellation of Cygnus

WR 137 is a variable Wolf-Rayet star located around 6,000 light years away from Earth in the constellation of Cygnus.

WR 111 is a Wolf-Rayet (WR) star in the constellation Sagittarius. It is magnitude 7.8 and lies about 5,150 light-years away. It is one of the brightest and most closely studied WR stars.

<span class="mw-page-title-main">HD 151932</span> Star in the constellation of Scorpius

HD 151932, also known as WR 78, is a Wolf-Rayet star located in the constellation Scorpius, close to the galactic plane. Its distance is around 1,300 parsecs away from the Earth. Despite being a blue-colored Wolf-Rayet star, it is extremely reddened by interstellar extinction, so its apparent magnitude is brighter for longer-wavelength passbands. HD 151932 lies about 22′ west of the open cluster NGC 6231, the center of the OB association Scorpius OB1; it is not clear whether it is a part of the association or not. With an apparent magnitude of about 6.5, it is one of the few Wolf-Rayet stars that can be seen with the naked eye.

<span class="mw-page-title-main">HD 152408</span> Star in the constellation of Scorpius

HD 152408, also known as WR 79a, is a Wolf-Rayet star located in the constellation Scorpius, close to the galactic plane. Its distance is around 2,020 parsecs away from the Earth.

<span class="mw-page-title-main">CV Serpentis</span>

CV Serpentis is a binary star system in the equatorial constellation of Serpens. It is a detached eclipsing binary with an orbital period of 29.7 days. The system includes a Wolf–Rayet (WR) star with the identifier WR 113. The system is located at a distance of approximately 6,700 light years from the Sun based on parallax measurements. It is a member of the Serpens OB2 association of co-moving stars.

<span class="mw-page-title-main">GG Carinae</span>

GG Carinae is a binary star system in the southern constellation of Carina, abbreviated GG Car. It is a variable star with a brightness that fluctuates around an apparent visual magnitude of 8.67, making it too faint to be visible to the naked eye. The distance to this system is approximately 8,000 light years based on parallax measurements.

References

  1. ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 4 March 2023.
  2. 1 2 3 4 5 6 Vallenari, A.; et al. (Gaia Collaboration) (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics . arXiv: 2208.00211 . doi: 10.1051/0004-6361/202243940 . Gaia DR3 record for this source at VizieR.
  3. 1 2 3 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. Bibcode:2017ARep...61...80S. doi: 10.1134/S1063772917010085 . S2CID   125853869.
  4. ↑ 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. arXiv: 1312.6222 . Bibcode:2014ApJS..211...10S. doi: 10.1088/0067-0049/211/1/10 .
  5. 1 2 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. arXiv: astro-ph/0311196 . Bibcode:2004ApJS..151..103M. doi: 10.1086/381380 .
  6. ↑ 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. arXiv: 1606.08053 . Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID   119231169.
  7. 1 2 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. Bibcode:1978ApJS...38..309H. doi: 10.1086/190559 .
  8. 1 2 3 4 5 6 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. arXiv: 0907.2539 . Bibcode:2009A&A...503..985C. doi: 10.1051/0004-6361/200912631 .
  9. ↑ 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. Bibcode:1997MNRAS.284..265H. doi: 10.1093/mnras/284.2.265 .
  10. ↑ Petit, V.; Wade, G. A.; Schneider, F. R. N.; Fossati, L.; Kamp, K.; Neiner, C.; David-Uraz, A.; Alecian, E.; MiMeS Collaboration (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. arXiv: 1909.00877 . Bibcode:2019MNRAS.489.5669P. doi: 10.1093/mnras/stz2469 .
  11. ↑ "HD 151804 -- Blue Supergiant". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2023-03-03.
  12. ↑ 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. 1 2 Hutchings, J. B. (1968). "Expanding atmospheres in OB supergiants-I". Monthly Notices of the Royal Astronomical Society. 141 (2): 219–249. Bibcode:1968MNRAS.141..219H. doi: 10.1093/mnras/141.2.219 .
  14. ↑ Campbell, W. W. (1894). "The Wolf-Rayet stars". Astronomy and Astro-Physics. 13: 448–476. Bibcode:1894AstAp..13..448C . Retrieved 8 March 2023.
  15. ↑ 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 .
  16. ↑ 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. Bibcode:1966MNRAS.131..247B. doi: 10.1093/mnras/131.2.247 .
  17. ↑ Morrison, N. D. (August 1975). "Photometry of O-type stars, interpreted with reference to model atmospheres". Astrophysical Journal. 200: 113–121. Bibcode:1975ApJ...200..113M. doi: 10.1086/153767 .
  18. ↑ van Genderen, A. M.; Bovenschen, H.; Engelsman, E. C.; Goudfrooy, P.; van Haarlem, M. P.; Hartmann, D.; Latour, H. J.; Ng, Y. K.; Prein, J. J.; van Roermund, F. H. P. M.; Roogering, H. J. A.; Steeman, F. W. M.; Tijdhof, W. (August 1989). "Light variations of massive stars (alpha Cygni variables). IX". Astronomy and Astrophysics Supplement Series. 79: 263–282. Bibcode:1989A&AS...79..263V.
  19. ↑ Kazarovets, E. V.; Samus, N. N. (October 1990). "The 70th Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 3530: 1. Bibcode:1990IBVS.3530....1K . Retrieved 8 March 2023.
  20. ↑ Ramiaramanantsoa, Tahina; Ratnasingam, Rathish; Shenar, Tomer; Moffat, Anthony F. J.; Rogers, Tamara M.; Popowicz, Adam; Kuschnig, Rainer; Pigulski, Andrzej; Handler, Gerald; Wade, Gregg A.; Zwintz, Konstanze; Weiss, Werner W. (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. arXiv: 1807.04660 . Bibcode:2018MNRAS.480..972R. doi: 10.1093/mnras/sty1897 .
  21. ↑ 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. arXiv: 2108.11734 . Bibcode:2022A&A...658A..61R. doi: 10.1051/0004-6361/202040116 .
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