Astronomy:HD 220689
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 23h 25m 52.99170s[1] |
| Declination | –20° 36′ 57.6998″[1] |
| Apparent magnitude (V) | +7.74[2] |
| Characteristics | |
| Spectral type | G3V[3] |
| B−V color index | +0.603±0.002[2] |
| Astrometry | |
| Radial velocity (Rv) | +12.30±0.14[1] km/s |
| Proper motion (μ) | RA: –15.328[1] mas/yr Dec.: –177.593[1] mas/yr |
| Parallax (π) | 21.3074 ± 0.0236[1] mas |
| Distance | 153.1 ± 0.2 ly (46.93 ± 0.05 pc) |
| Absolute magnitude (MV) | 4.50[2] |
| Details[4] | |
| Mass | 1.016±0.048 M☉ |
| Radius | 1.068±0.047 R☉ |
| Luminosity | 1.491±0.005[5] L☉ |
| Surface gravity (log g) | 4.360±0.045 cgs |
| Temperature | 5,921±26 K |
| Metallicity [Fe/H] | −0.07±0.10 dex |
| Rotation | ~29 d |
| Rotational velocity (v sin i) | 5.5[6] km/s |
| Age | 4.586±2.487 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| Extrasolar Planets Encyclopaedia | data |
HD 220689 is a single[8] star in the equatorial constellation of Aquarius. It is a challenge to view with the naked eye, having an apparent visual magnitude of +7.74,[2] but is readily viewed with a pair of binoculars.[9] The star is located at a distance of 153 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +12 km/s.[1] A survey in 2015 has ruled out the existence of any additional stellar companions at projected distances from 26 to 305 astronomical units.[8]
The stellar classification of HD 220689 is G3V,[3] matching a yellow hued G-type main-sequence star that is generating energy through core hydrogen fusion. It is roughly 4.6 billion years old and is spinning with a projected rotational velocity of 5.5 km/s,[6] giving it a rotation period of around 29 days.[4] The star has a similar size, mass, and elemental abundances as the Sun. It is radiating 1.5[5] times the luminosity of the Sun from its photosphere at an effective temperature of 5,921 K.[4]
Planetary system
From 1998 to 2012, the star was under observation from the CORALIE echelle spectrograph at La Silla Observatory. In 2012, a long-period, wide-orbiting exoplanet was deduced from radial velocity variations. This was published in November.[10] The maximum orbital period allowing for dynamic stability of a hypothetical inner planet is 3.9 years.[4] In 2023, the inclination and true mass of HD 220689 b were determined via astrometry.[11]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (years) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 1.2+0.22 −0.11 MJ |
3.433+0.065 −0.064 |
6.23+0.15 −0.14 |
0.053+0.06 −0.037 |
71+13 −18 or 109+18 −13° |
— |
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 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.
- ↑ 2.0 2.1 2.2 2.3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Houk, Nancy; Smith-Moore, M. (1978). Michigan catalogue of two-dimensional spectral types for the HD stars. 4. Ann Arbor: Dept. of Astronomy, University of Michigan. Bibcode: 1988mcts.book.....H.
- ↑ 4.0 4.1 4.2 4.3 Barbato, D. et al. (August 2018). "Exploring the realm of scaled solar system analogues with HARPS". Astronomy & Astrophysics 615: 21. doi:10.1051/0004-6361/201832791. A175. Bibcode: 2018A&A...615A.175B.
- ↑ 5.0 5.1 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.
- ↑ 6.0 6.1 Luck, R. Earle (March 2018). "Abundances in the Local Region. III. Southern F, G, and K Dwarfs". The Astronomical Journal 155 (3): 31. doi:10.3847/1538-3881/aaa9b5. 111. Bibcode: 2018AJ....155..111L.
- ↑ "HD 220689". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+220689.
- ↑ 8.0 8.1 Mugrauer, M.; Ginski, C. (12 May 2015). "High-contrast imaging search for stellar and substellar companions of exoplanet host stars". Monthly Notices of the Royal Astronomical Society 450 (3): 3127–3136. doi:10.1093/mnras/stv771. Bibcode: 2015MNRAS.450.3127M. https://academic.oup.com/mnras/article/450/3/3127/1063872. Retrieved 19 June 2020.
- ↑ "The astronomical magnitude scale". International Comet Quarterly. http://www.icq.eps.harvard.edu/MagScale.html.
- ↑ Marmier, M. et al. (2013). "The CORALIE survey for southern extrasolar planets XVII. New and updated long period and massive planets". Astronomy and Astrophysics 551: A90. doi:10.1051/0004-6361/201219639. Bibcode: 2013A&A...551A..90M.
- ↑ 11.0 11.1 Xiao, Guang-Yao et al. (March 2023). "The Masses of a Sample of Radial-Velocity Exoplanets with Astrometric Measurements". Research in Astronomy and Astrophysics.
External links
- "HD 220689 b". Extrasolar Planets Encyclopaedia. https://exoplanet.eu/catalog/hd_220689_b--981/. Retrieved 2021-01-02.
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