WR 102ka

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WR 102ka
Peony nebula.jpg
The "Peony Nebula," as discovered by NASA's Spitzer Space Telescope. This three-color infrared composite shows 3.6-micrometre light in blue, 8-micrometre light in green, and 24-micrometre light in red. The Peony nebula is the reddish cloud of dust in and around the white circle, surrounding the Peony nebular star.
Observation data
Epoch J2000.       Equinox J2000.
Constellation Sagittarius
Right ascension 17h 46m 18.12s [1]
Declination −29° 01′ 36.5″ [1]
Characteristics
Evolutionary stage Slash star
Spectral type Ofpe/WN9 [2]
Apparent magnitude  (J)13.0 [1]
Apparent magnitude  (H)10.3 [1]
Apparent magnitude  (K)8.8 [1]
J−H color index 2.7 [1]
J−K color index 4.2 [1]
Variable type
Astrometry
Distance 26,000 [2]   ly
(8,000 [2]   pc)
Details
Mass ~100 [3]   M☉
Radius 92 [2]   R☉
Luminosity 2,950,000 [3]   L☉
Temperature 25,100 [2] [3]   K
Age ~2 [3]   Myr
Other designations
Peony Star, [4] Peony nebula star, WR  102ka, 2MASS  J17461811-2901366, ISOGAL-P J174618.2-290136, MSX6C  G000.0003-00.1743
Database references
SIMBAD data

WR 102ka, also known as the Peony star, is a slash star that is one of several candidates for the most luminous-known star in the Milky Way. [5]

Contents

Discovery

WR 102ka lies near the Galactic Center and is essentially totally obscured in visible wavelengths. Thus it must be observed in longer wavelength infrared light, which is able to penetrate the dust. WR 102ka was catalogued in 2002 and 2003 by infrared surveys. It was observed for the Two-Micron All Sky Survey (2MASS) in the near-infrared J, H, and Ks bands, at 1.2 μm, 1.58 μm, and 2.2 μm, respectively, [1] and the ISOGAL survey of candidate young stellar objects at 7 μm and 15 μm. [6]

Narrowband infrared observations of several spectral features around 2 μm showed that WR 102ka was a Wolf Rayet star with a likely classification of WN10. [7] It was also proposed as a possible luminous blue variable. [8]

The Spitzer Space Telescope observed WR 102ka at wavelengths of 3.6 μm, 8 μm, and 24 μm on April 20, 2005. These observations allowed the first reliable calculations of the physical properties of this extremely luminous object. [2]

Other luminous Milky Way stars

The closer star WR 25 may be more luminous than WR 102ka. [9] Another nearer star, Eta Carinae, which was the second-brightest star in the sky for a few years in the 19th century, appears to be slightly more luminous than WR 102ka, but is known to be a binary star system. There is also the more recently discovered Pistol Star that, like the Peony star, derives its name from the shape of the nebula in which it is embedded, and which it has probably created through heavy mass loss via strong stellar winds and perhaps also "mini-supernova-like" eruptions as happened to Eta Carinae around the 1830s–1840s creating the lobes observed by the Hubble Space Telescope. [10]

The luminosities of the Pistol Star, Eta Carinae, and WR 102ka are all rendered somewhat uncertain due to heavy obscuration by galactic dust in the foreground, the effects of which must be corrected for before their apparent brightness can be reduced to estimate their total radiated power or bolometric luminosity. [11] Both Eta Carinae and WR 102ka are believed likely to explode as supernovas or hypernovae within the next few million years. [12] [9] As is typical of such extremely massive and luminous stars, both have expelled a considerable portion of their initial mass, when originally formed, in dense, massive stellar winds. [13] [9]

See also

Related Research Articles

<span class="mw-page-title-main">Carina Nebula</span> Interstellar clouds in the constellation Carina

The Carina Nebula or Eta Carinae Nebula is a large, complex area of bright and dark nebulosity in the constellation Carina, located in the Carina–Sagittarius Arm of the Milky Way galaxy. The nebula is approximately 8,500 light-years (2,600 pc) from Earth.

<span class="mw-page-title-main">WR 136</span> Star in the constellation of Cygnus

WR 136 is a Wolf–Rayet star located in the constellation Cygnus. It is in the center of the Crescent Nebula. Its age is estimated to be around 4.7 million years and it is nearing the end of its life. Within a few hundred thousand years, it is expected to explode as a supernova.

<span class="mw-page-title-main">Quintuplet cluster</span> Dense star cluster of massive young stars in the constellation of Sagittarius

The Quintuplet cluster is a dense cluster of massive young stars about 100 light years from the Galactic Center (GC). Its name comes from the fact it has five prominent infrared sources residing in it. Along with the Arches Cluster it is one of two in the immediate GC region. Due to heavy extinction by dust in the vicinity, it is invisible to optical observation and must be studied in the X-ray, radio, and infrared bands.

<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">WR 102ea</span> Star in the constellation Sagittarius

WR 102ea is a Wolf–Rayet star in the Sagittarius constellation. It is the third most luminous star in the Quintuplet cluster after WR 102hb. With a luminosity of 2,500,000 times solar, it is also one of the most luminous stars known. Despite the high luminosity it can only be observed at infra-red wavelengths due to the dimming effect of intervening dust on visual light.

<span class="mw-page-title-main">WR 22</span> Binary star 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">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">WR 102c</span>

WR 102c is a Wolf–Rayet star located in the constellation Sagittarius towards the galactic centre. It is only a few parsecs from the Quintuplet Cluster, within the Sickle Nebula.

WR 147 is a multiple star system in the constellation of Cygnus. The system is extremely reddened by interstellar extinction - that is, dust in front of the star scatters much of the blue light coming from WR 147, leaving the star appearing reddish.

<span class="mw-page-title-main">WR 148</span> Binary star in the constellation of Cygnus

WR 148 is a spectroscopic binary in the constellation Cygnus. The primary star is a Wolf–Rayet star and one of the most luminous stars known. The secondary has been suspected of being a stellar-mass black hole but may be a class O main sequence star.

WR 156 is a young massive and luminous Wolf–Rayet star in the constellation of Cepheus. Although it shows a WR spectrum, it is thought to be a young star still fusing hydrogen in its core.

<span class="mw-page-title-main">Trumpler 16</span> Massive open cluster in the constellation Carina

Trumpler 16 is a massive open cluster that is home to some of the most luminous stars in the Milky Way galaxy. It is situated within the Carina Nebula complex in the Carina–Sagittarius Arm, located approximately 9,270 ly (2,842 pc) from Earth. The cluster has one star visible to the naked eye from the tropics southward, Eta Carinae.

WR 142 is a Wolf-Rayet star in the constellation Cygnus, an extremely rare star on the WO oxygen sequence. It is a luminous and very hot star, highly evolved and close to exploding as a supernova. It is suspected to be a binary star with a companion orbiting about 1 AU away.

<span class="mw-page-title-main">WR 102</span> Star in the constellation Sagittarius

WR 102 is a Wolf–Rayet star in the constellation Sagittarius, an extremely rare star on the WO oxygen sequence. It is a luminous and very hot star, highly evolved and close to exploding as a supernova.

WR 114 is a Wolf-Rayet star in the constellation of Scutum. It is an early type star of the carbon sequence (WCE) classified as WC5.

WR 2 is a Wolf-Rayet star located around 8,000 light years away from Earth in the constellation of Cassiopeia, in the stellar association Cassiopeia OB1. It is smaller than the Sun, but due to a temperature over 140,000 K it is 282,000 times as luminous as the Sun. With a radius of 89% that of the Sun, it is the smallest known WN star in the Milky Way.

WR 150 is a Wolf-Rayet star in the constellation of Cygnus. It is one of the early-type carbon sequence (WCE), and is of spectral type WC5. WR 150 is very far from the Earth, being 28,500 light-years from it.

WR 119 is a Wolf–Rayet star located about 10,500 light years away in the constellation Scutum. WR 119 is classified as a WC9 star, belonging to the late-type carbon sequence of Wolf-Rayet stars. WR 119 is noteworthy for being the least luminous known Wolf-Rayet star, at just over 50,000 L☉. The most recent estimate is even lower, at just 42,700 L☉, based on the most recent analysis using Gaia DR2 data.

References

  1. 1 2 3 4 5 6 7 8 Skrutskie, Michael F.; Cutri, Roc M.; Stiening, Rae; Weinberg, Martin D.; Schneider, Stephen E.; Carpenter, John M.; et al. (1 February 2006). "The Two Micron All Sky Survey (2MASS)". The Astronomical Journal. 131 (2): 1163–1183. Bibcode:2006AJ....131.1163S. doi: 10.1086/498708 . ISSN   0004-6256. S2CID   18913331.
  2. 1 2 3 4 5 6 Barniske, A.; Oskinova, L. M.; Hamann, W. -R. (2008). "Two extremely luminous WN stars in the Galactic center with circumstellar emission from dust and gas". Astronomy and Astrophysics. 486 (3): 971. arXiv: 0807.2476 . Bibcode:2008A&A...486..971B. doi:10.1051/0004-6361:200809568. S2CID   8074261.
  3. 1 2 3 4 Oskinova, L. M.; Steinke, M.; Hamann, W. - R.; Sander, A.; Todt, H.; Liermann, A. (2013). "One of the most massive stars in the Galaxy may have formed in isolation". Monthly Notices of the Royal Astronomical Society. 436 (4): 3357. arXiv: 1309.7651 . Bibcode:2013MNRAS.436.3357O. doi:10.1093/mnras/stt1817. S2CID   118513968.
  4. ↑ Hamann, Wolf-Rainer; Barniske, Andreas; Liermann, Adriane; Oskinova, Lidia M.; Pasemann, Diana; Ruehling, Ute (2011). "The most luminous stars in the Galaxy and the Magellanic Clouds". Société Royale des Sciences de Liège. 80: 98. arXiv: 1012.1875v1 . Bibcode:2011BSRSL..80...98H.
  5. ↑ Steinke, M.; Oskinova, L. M.; Hamann, W. -R.; Sander, A. (2015-01-01). "The Wolf-Rayet stars WR102c and 102ka and their isolation". Wolf-Rayet Stars: 365. Bibcode:2015wrs..conf..365S.
  6. ↑ Felli, M.; Testi, L.; Schuller, F.; Omont, A. (2002). "Young massive stars in the ISOGAL survey. II. The catalogue of bright YSO candidates". Astronomy and Astrophysics. 392 (3): 971–990. arXiv: astro-ph/9905296 . Bibcode:2002A&A...392..971F. doi:10.1051/0004-6361:20020973. S2CID   18314394.
  7. ↑ Homeier, N. L.; Blum, R. D.; Pasquali, A.; Conti, P. S.; Damineli, A. (2003). "Results from a near infrared search for emission-line stars in the Inner Galaxy: Spectra of new Wolf-Rayet stars". Astronomy & Astrophysics. 408: 153–159. arXiv: astro-ph/0306578 . Bibcode:2003A&A...408..153H. doi:10.1051/0004-6361:20030989. S2CID   11814077.
  8. ↑ Clark, J. S.; Larionov, V. M.; Arkharov, A. (2005). "On the population of galactic Luminous Blue Variables" (PDF). Astronomy & Astrophysics. 435 (1): 239–246. Bibcode:2005A&A...435..239C. doi: 10.1051/0004-6361:20042563 .
  9. 1 2 3 "WR 102ka – a Blue Supergiant Star - Assignment Point" . Retrieved 2022-03-08.
  10. ↑ Garner, Rob (2019-07-01). "Hubble Captures the Galaxy's Biggest Ongoing Stellar Fireworks Show". NASA. Retrieved 2022-03-08.
  11. ↑ Zwicky, F. (1962). "1962IAUS...15..347Z Page 347". Problems of Extra-Galactic Research. 15: 347. Bibcode:1962IAUS...15..347Z . Retrieved 2022-03-08.
  12. ↑ Elizabeth Howell (2022-01-26). "Eta Carinae's epic supernova explosion comes to life in new visualization". Space.com. Retrieved 2022-03-08.
  13. ↑ "The turbulent heart of Eta Carinae". www.mpg.de. Retrieved 2022-03-08.
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