WR 156
In today's world, WR 156 has become a topic of relevance and interest to a wide spectrum of society. Whether due to its impact on popular culture, politics, technology or people's daily lives, WR 156 has managed to capture the attention of millions of people around the world. Over the years, WR 156 has been the subject of debate, analysis and reflection, generating a great diversity of opinions and points of view that reflect the complexity and importance of this topic. In this article, we will explore the various facets of WR 156 and its influence in different areas of modern life, with the aim of shedding light on a topic that continues to be relevant today.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Cepheus[1] |
| Right ascension | 23h 00m 10.12539s[2] |
| Declination | +60° 55′ 38.4109″[2] |
| Apparent magnitude (V) | 11.01[3] |
| Characteristics | |
| Spectral type | WN8h[4] |
| B−V color index | +1.17[3] |
| Astrometry | |
| Proper motion (μ) | RA: −2.596[2] mas/yr Dec.: −1.768[2] mas/yr |
| Parallax (π) | 0.2749±0.0125 mas[2] |
| Distance | 11,900 ± 500 ly (3,600 ± 200 pc) |
| Absolute magnitude (MV) | −7.00[5] |
| Details | |
| Mass | 32[5] M☉ |
| Radius | 20.81[5] R☉ |
| Luminosity | 1,023,000[5] L☉ |
| Temperature | 39,800[5] K |
| Other designations | |
| WR 156, HIP 113569, 2MASS J23001010+6055385, MR 119 | |
| Database references | |
| SIMBAD | data |
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.
Distance
WR 156 has a Hipparcos parallax of 3.16" indicating a distance of about a thousand light years, although with a fairly large margin of error. Other studies indicate that it is much more distant based on a very high luminosity and faint apparent magnitude.[5] The Gaia DR1 parallax is 0.07". The margin of error is larger than the measured parallax, but still the indication is for a very large distance.[6] In Gaia Data Release 2, the parallax is given as 0.2090±0.0251 mas but with a marker that the result may be unreliable.[7] In Gaia Data Release 3, the solution was adjusted to 0.2749±0.0125 mas, still with significant astrometric noise excess.[2]
Physical properties
WR 156 has a WR spectrum on the nitrogen sequence, indicating strong emission of helium and nitrogen, but it also shows features of hydrogen. Therefore, it is given a spectral type of WN8h. Its outer layers are calculated to contain 30% hydrogen, one of the highest levels for any galactic Wolf Rayet star.[8]
WR 156 has a low temperature and slow stellar wind by Wolf Rayet standards, only 39,800 K and 660 km/s respectively. The wind is very dense, with total mass loss of more than 1/100,000 M☉/year.[5]
WR 156 is a young hydrogen-rich star, still burning hydrogen in its core but sufficiently luminous to have convected up nitrogen and helium fusion products to its surface. It shows 27% hydrogen at its surface.[5] It is estimated to have had an initial mass of 50 M☉ several million years ago.[8]
References
- ^ Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015.
- ^ a b c d e f Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27. Bibcode:2000A&A...355L..27H. doi:10.1888/0333750888/2862. ISBN 0333750888.
- ^ Maryeva, Olga (2016). "The study of massive stars with 50 Msun initial mass at different evolutionary stages". arXiv:1612.01191 .
- ^ a b c d e f g h Sota, A.; Maíz Apellániz, J.; Morrell, N. I.; Barbá, R. H.; Walborn, N. R.; Gamen, R. C.; Arias, J. I.; Alfaro, E. J.; Oskinova, L. M. (2019). "The Galactic WN stars revisited. Impact of Gaia distances on fundamental stellar parameters". Astronomy & Astrophysics. A57: 625. arXiv:1904.04687. Bibcode:2019A&A...625A..57H. doi:10.1051/0004-6361/201834850. S2CID 104292503.
- ^ Gaia Collaboration (2016). "VizieR Online Data Catalog: Gaia DR1 (Gaia Collaboration, 2016)". VizieR On-line Data Catalog: I/337. Originally Published in: Astron. Astrophys. 1337. Bibcode:2016yCat.1337....0G. doi:10.26093/cds/vizier.1337.
- ^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b Maryeva, O. V.; Afanasiev, V. L.; Panchuk, V. E. (2013). "Study of the late nitrogen-sequence Galactic Wolf-Rayet star WR156. Spectropolarimetry and modeling". New Astronomy. 25: 27–31. Bibcode:2013NewA...25...27M. doi:10.1016/j.newast.2013.03.015.
