HD 149404

Last updated
HD 149404
V918ScoLightCurve.png
A light curve for V918 Scorpii, plotted from TESS data. [1] The inset plot shows the same data folded with the orbital period, and averaged into 100 bins per orbit.
Observation data
Epoch J2000.0        Equinox J2000.0
Constellation Scorpius
Right ascension 16h 36m 22.56285s [2]
Declination −42° 51′ 31.9021″ [2]
Apparent magnitude  (V)5.42 - 5.50 [3]
Characteristics
Spectral type O7.5I(f) + ON9.7I [4]
U−B color index −0.55 [5]
B−V color index +0.40 [5]
Variable type ELL [3]
Astrometry
Proper motion (μ)RA: −3.375±0.081 [2]   mas/yr
Dec.: −3.306±0.069 [2]   mas/yr
Parallax (π)0.7601 ± 0.0709  mas [2]
Distance 4,300 ± 400  ly
(1,300 ± 100  pc)
Orbit [4]
Period (P)9.81475  d
Eccentricity (e)0.0 (assumed)
Periastron epoch (T)2451680.279±0.174
Semi-amplitude (K1)
(primary)		59.7±2.0 km/s
Semi-amplitude (K2)
(secondary)		98.7±3.2 km/s
Details
Primary
Mass 50.5±20.1 [6]   M☉
Radius 19.3±2.2 [6]   R☉
Luminosity 430000+52000
−46000 [6]   L☉
Surface gravity (log g)3.55±0.15} [6]   cgs
Temperature 34000±0.15 [6]   K
Secondary
Mass 31.9±9.5 [6]   M☉
Radius 25.9±3.4 [6]   R☉
Luminosity380000+37000
−34000 [6]   L☉
Surface gravity (log g)3.05±0.15 [6]   cgs
Temperature 28000±0.15 [6]   K
Other designations
V918 Sco, HIP  81305, HR  6164, SAO  226953 [7]
Database references
SIMBAD data

HD 149404, also known as HR 6164 and V918 Scorpii, is a star about 4,300 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. [2] It is a rotating ellipsoidal variable, a binary star for which the two stars' combined brightness varies slightly, from magnitude 5.42 to 5.50, during their 9.8 day orbital period. [3] It is one of the brightest members of the Ara OB1 association, which has the open cluster NGC 6193 at its center. [8]

The brightness variability of HD 149404 was marginally detected by the Argentinian astronomer Alenjandro Feinstein, during a photoelectric photometry study undertaken from 1963 through 1965. [9] It was given the variable star designation V918 Scorpii in 1980. [10] In 1977, Peter Conti et al. discovered that HD 149404 has double spectral lines, implying it is a spectroscopic binary. [11] Philip Massey and Peter Conti derived the first set of orbital elements for the binary system, in 1979. [12]

The secondary star in the HD 149404 system is believed to have originally been the more massive of the two, but it is now less massive than the primary due to mass transfer caused by Roche lobe overflow in the past. [6] The secondary may still be close to filling its Roche lobe. [4] It is a rare ON supergiant, a star with unusually strong absorption lines of nitrogen in its stellar spectrum. [13] Spectroscopic studies show that both stars have a stellar wind and a shock is formed where the two winds collide, which produces emission line features. [4]

Related Research Articles

<span class="mw-page-title-main">Iota Orionis</span> Multiple star system in the constellation Orion

Iota Orionis is a multiple star system in the equatorial constellation of Orion the hunter. It is the eighth-brightest member of Orion with an apparent visual magnitude of 2.77 and also the brightest member of the asterism known as Orion's Sword. It is a member of the NGC 1980 open cluster. From parallax measurements, it is located at a distance of roughly 1,340 light-years from the Sun.

3 Centauri is a triple star system in the southern constellation of Centaurus, located approximately 300 light years from the Sun. It is visible to the naked eye as a faint, blue-white hued star with a combined apparent visual magnitude of 4.32. As of 2017, the two visible components had an angular separation of 7.851″ along a position angle of 106°. The system has the Bayer designation k Centauri; 3 Centauri is the Flamsteed designation. It is a suspected eclipsing binary with a variable star designation V983 Centauri.

<span class="mw-page-title-main">HD 93250</span> Highly luminous binary star system in the constellation Carina

HD 93250 is a highly luminous hot blue binary star in the Carina Nebula in the constellation Carina.

Cygnus OB2 #8A is a double-lined spectroscopic binary located near the centre of the Cygnus OB2 association located 5,500 light years away.

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

HR Carinae is a luminous blue variable star located in the constellation Carina. It is surrounded by a vast nebula of ejected nuclear-processed material because this star has a multiple shell expanding atmosphere. This star is among the most luminous stars in the Milky Way. It has very broad emission wings on the Balmer lines, reminiscent from the broad lines observed in the spectra of O and Wolf–Rayet stars. A distance of 5 kpc and a bolometric magnitude of -9.4 put HR Car among the most luminous stars of the galaxy.

<span class="mw-page-title-main">HD 150136</span> Multiple star system in the constellation Ara

HD 150136 is a multiple star system in the southern constellation of Ara, around 4,300 light years away. It is the brightest member of the faint open cluster NGC 6193, part of the Ara OB1 association.

<span class="mw-page-title-main">HD 48099</span> Binary star system in the constellation Monoceros

HD 48099 is a spectroscopic binary in the constellation Monoceros where both components are massive and luminous O stars.

<span class="mw-page-title-main">WR 22</span> Eclipsing binary star system in the constellation Carina

WR 22, also known as V429 Carinae or HR 4188, is an eclipsing binary star system in the constellation Carina. The system contains a Wolf-Rayet (WR) star that is one of the most massive and most luminous stars known, and is also a bright X-ray source due to colliding winds with a less massive O class companion. Its eclipsing nature and apparent magnitude make it very useful for constraining the properties of luminous hydrogen-rich WR stars.

<span class="mw-page-title-main">HD 168625</span> Star in the constellation Sagittarius

HD 168625 is a blue hypergiant star and candidate luminous blue variable located in the constellation of Sagittarius easy to see with amateur telescopes. It forms a visual pair with the also blue hypergiant HD 168607 and is located to the south-east of M17, the Omega Nebula.

<span class="mw-page-title-main">HD 168607</span> Star in the constellation Sagittarius

HD 168607 is a blue hypergiant and luminous blue variable (LBV) star located in the constellation of Sagittarius, easy to see with amateur telescopes. It forms a pair with HD 168625, also a blue hypergiant and possible luminous blue variable, that can be seen at the south-east of M17, the Omega Nebula.

<span class="mw-page-title-main">WR 46</span> Star in the constellation Crux

WR 46 is a Wolf-Rayet star in the constellation of the Southern Cross of apparent magnitude +10.8. It is located at 55 arcmin north of Theta2 Crucis. The star is a member of the distant stellar association OB4 Cru, and is around 2,900 parsecs or 9,300 light years from the Solar System.

<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">HD 160529</span> Luminous blue variable star in the constellation Scorpius

HD 160529 is a luminous blue variable (LBV) star located in the constellation of Scorpius. With an apparent magnitude of around +6.8 cannot be seen with the naked eye except under very favourable conditions, but it is easy to see with binoculars or amateur telescopes.

<span class="mw-page-title-main">HD 21278</span> Binary star system in the constellation Perseus

HD 21278 is a binary star system in the constellation Perseus, located within the 60±7 million year old Alpha Persei Cluster. It has a blue-white hue and is visible to the naked eye with a combined apparent visual magnitude of 4.99. The system is located at a distance of approximately 580 light years from the Sun based on parallax, and it is drifting further away with a radial velocity of +1.20 km/s.

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

N Scorpii, also known as HD 148703, is a solitary, bluish-white hued star located in the southern constellation Scorpius. It has an apparent magnitude of 4.23, making it readily visible to the naked eye. N Scorpii was initially given the Bayer designation Alpha Normae by Lacaille but it was later moved from Norma to Scorpius. N Scorpii is currently located 550 light years away based on parallax measurements from the Hipparcos satellite and is part of the Upper Scorpius–Centaurus region of the Scorpius–Centaurus association.

HD 93403 is a spectroscopic binary containing two highly luminous hot blue stars. It is 10,000 light years away in the Carina Nebula in the constellation Carina. It appears to have spectral type O5.5III, but this is composed of two spectra from a blue supergiant and blue main sequence star of spectral type O5.5I and O7V respectively. The two stars orbit every 15 days with a separation that varies from 93 R☉ to 149 R☉. The binary is shedding mass at the high rate of 0.0005 M☉ per year.

<span class="mw-page-title-main">HD 316285</span> Star in the constellation Sagittarius

HDE 316285 is a blue supergiant star in the constellation Sagittarius. It is a candidate luminous blue variable and lies about 6,000 light years away in the direction of the galactic centre.

<span class="mw-page-title-main">HD 15558</span> Star in the constellation Cassiopeia

HD 15558 is a massive O-type multiple star system in Cassiopeia and is specifically in our galaxy's Heart Nebula in open cluster IC 1805. The primary is a very massive star with 152 M☉ and 660,000 L☉.

<span class="mw-page-title-main">V957 Scorpii</span>

V957 Scorpii is a variable star in the constellation of Scorpius. It is a blue straggler in the open cluster Messier 7, a star that is unexpectedly hot compared to other members of the cluster.

<span class="mw-page-title-main">HD 159176</span> Variable star in the constellation Scorpius

HD 159176, also known as Boss 4444 and V1036 Scorpii, is a variable star about 2,800 light years from the Earth, in the constellation Scorpius. It is a 5th magnitude star, so it should be visible to the naked eye of an observer far from city lights. HD 159176 is the brightest star in the young open cluster NGC 6383. It is a binary star composed of two nearly identical O stars in a circular orbit.

References

  1. ↑ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 19 February 2023.
  2. 1 2 3 4 5 6 7 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 N. N. Samus; O. V. Durlevich; et al. "V918 Sco database entry". Combined General Catalog of Variable Stars (2017 ed.). CDS . Retrieved 2023-02-19.
  4. 1 2 3 4 Rauw, G.; Nazé, Y.; Carrier, F.; Burki, G.; Gosset, E.; Vreux, J. M. (March 2001). "The strange case of the massive binary HD 149404". Astronomy and Astrophysics. 368: 212–224. Bibcode:2001A&A...368..212R. doi: 10.1051/0004-6361:20000527 .
  5. 1 2 Humphreys, R. M. (January 1975). "Spectroscopic and photometric observations of luminous stars in the Centaurus-Norma (l = 305 - 340 ) section of the Milky Way". Astronomy and Astrophysics Suppl. Ser. 19: 243–247. Bibcode: 1975A&AS...19..243H .
  6. 1 2 3 4 5 6 7 8 9 10 11 Raucq, F.; Rauw, G.; Gosset, E.; Nazé, Y.; Mahy, L.; Hervé, A.; Martins, F. (April 2016). "Observational signatures of past mass-exchange episodes in massive binaries: The case of HD 149 404". Astronomy and Astrophysics. 588: A10. arXiv: 1601.08083 . Bibcode:2016A&A...588A..10R. doi: 10.1051/0004-6361/201527543 .
  7. ↑ "HD 149404 -- Blue Supergiant". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2023-02-18.
  8. ↑ Thaller, M. L.; Gies, D. R.; Fullerton, A. W.; Kaper, L.; Wiemker, R. (June 2001). "A Spectroscopic Search for Colliding Stellar Winds in O-Type Close Binary Systems. V. HD 149404". The Astrophysical Journal. 554 (2): 1070–1078. Bibcode:2001ApJ...554.1070T. doi: 10.1086/321409 .
  9. ↑ Feinstein, A. (1968). "A Survey of Southern Be Stars. II. Photometric data". Zeitschrift für Astrophysik. 68: 29–47. Bibcode: 1968ZA.....68...29F .
  10. ↑ Kholopov, P. N.; Samus, N. N.; Kukarkina, N. P.; Medvedeva, G. I.; Perova, N. B. (February 1981). "65th Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 1921: 1. Bibcode:1981IBVS.1921....1K . Retrieved 21 February 2023.
  11. ↑ Conti, P. S.; Leep, E. M.; Lorre, J. J. (June 1977). "Spectroscopic studies of O-type stars. VIII. Radial velocities and the K-term". Astrophysical Journal. 214: 759–772. Bibcode: 1977ApJ...214..759C . doi:10.1086/155305.
  12. ↑ Massey, P.; Conti, P. S. (1979). "The O-type spectroscopic binary system HD 149404". IAU Symposium. 83: 271–275. Bibcode: 1979IAUS...83..271M .
  13. ↑ Walborn, N. R.; Panek, R. J. (1985). "Ultraviolet spectral morphology of the O stars. III. The ON and OC stars". The Astrophysical Journal. 291: 806. Bibcode:1985ApJ...291..806W. doi:10.1086/163116.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.