Astronomy:HD 180450
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Lyra[1] |
| Right ascension | 19h 15m 24.859s[2] |
| Declination | +30° 31′ 34.98″[2] |
| Apparent magnitude (V) | 5.88[1] |
| Characteristics | |
| Evolutionary stage | AGB[3] |
| Spectral type | M1IIIab[1] |
| U−B color index | +2.03[citation needed] |
| B−V color index | +1.665±0.007[1] |
| Astrometry | |
| Radial velocity (Rv) | −64.43±0.23[4] km/s |
| Proper motion (μ) | RA: 34.374[2] mas/yr Dec.: −26.212[2] mas/yr |
| Parallax (π) | 3.4206 ± 0.0625[2] mas |
| Distance | 950 ± 20 ly (292 ± 5 pc) |
| Absolute magnitude (MV) | −2.03[1] |
| Details | |
| Mass | 1.4[5] M☉ |
| Radius | 84[6] R☉ |
| Luminosity | 1,218[6] L☉ |
| Surface gravity (log g) | 1.58[5] cgs |
| Temperature | 3,733[6] K |
| Metallicity [Fe/H] | −0.23[5] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
HD 180450 is a single[8] star in the northern constellation of Lyra, positioned about half a degree to the NNW of the globular cluster M56.[9] At an apparent visual magnitude of 5.88,[1] it is dimly visible to the naked eye under good viewing conditions. This star is located at a distance of approximately 950 light years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −64.4 km/s.[4]
This is an aging red giant star with a stellar classification of M1IIIab.[1] It is currently on the asymptotic giant branch,[10] having exhausted the supply of hydrogen in its core and evolved off the main sequence. The star has expanded to ~68 times the radius of the Sun and is radiating a thousand times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,947 K.[4]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A. XHIP record for this object at VizieR.
- ↑ 2.0 2.1 2.2 2.3 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.
- ↑ Eggen, Olin J. (1992). "Asymptotic Giant Branch Stars Near the Sun". The Astronomical Journal 104: 275. doi:10.1086/116239. Bibcode: 1992AJ....104..275E.
- ↑ 4.0 4.1 4.2 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 5.0 5.1 5.2 Khalatyan, A. et al. (2024). "Transferring spectroscopic stellar labels to 217 million Gaia DR3 XP stars with SHBoost". Astronomy and Astrophysics 691: A98. doi:10.1051/0004-6361/202451427. Bibcode: 2024A&A...691A..98K.
- ↑ 6.0 6.1 6.2 Van Belle, Gerard T. et al. (2021). "Direct Measurements of Giant Star Effective Temperatures and Linear Radii: Calibration against Spectral Types and V - K Color". The Astrophysical Journal 922 (2): 163. doi:10.3847/1538-4357/ac1687. Bibcode: 2021ApJ...922..163V.
- ↑ "HD 180450". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+180450.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Sinnott, Roger W.; Perryman, Michael A. C. (1997), Millennium Star Atlas, 3, Sky Publishing Corporation and the European Space Agency, p. 1174, ISBN 0-933346-84-0.
- ↑ Eggen, Olin J. (July 1992), "Asymptotic giant branch stars near the sun", Astronomical Journal 104 (1): 275–313, doi:10.1086/116239, Bibcode: 1992AJ....104..275E.
 |  |
