| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Crater |
| Right ascension | 11h 17m 47.5531s [1] |
| Declination | –23° 58′ 31.4952″ [1] |
| Apparent magnitude (V) | +8.05 [2] |
| Characteristics | |
| Spectral type | K0III/IV [3] |
| Astrometry | |
| Radial velocity (Rv) | -10.30 [1] km/s |
| Proper motion (μ) |
RA: −130.770±0.068
[1]
mas/
yr Dec.: −16.887±0.050 [1] mas/ yr |
| Parallax (π) | 8.7662 ± 0.0489 mas [1] |
| Distance | 372 ± 2
ly (114.1 ± 0.6 pc) |
| Absolute magnitude (MV) | +2.6 [4] |
| Details | |
| Mass | 1.41 [2] M☉ |
| Radius | 4.6 [2] R☉ |
| Luminosity | 8.284 [1] L☉ |
| Surface gravity (log g) | 3.36 [2] cgs |
| Temperature | 4,925 [2] K |
| Age | 4 [4] Gyr |
| Database references | |
| SIMBAD | data |
HD 98219, also named Hunahpú, is a subgiant star in the constellation Crater. It has a confirmed exoplanet. At around 4 billion years old, it is a star around 1.3 times as massive as the Sun that has cooled and expanded to 4.5 times the Sun's diameter, brightening to be around 11 times as luminous. [4] The International Astronomical Union ( IAU) gave the opportunity to Honduras to name the star Hunahpú as part of NameExoWorlds. Hunahpú was one of the twin gods who became the Sun in K'iche' (Quiché) Mayan mythology. [5]
Planetary system
A gas giant planet with a minimum mass almost double that of Jupiter was discovered as part of a radial velocity survey of subgiant stars at Keck Observatory. [4] The International Astronomical Union ( IAU) has named it Ixbalanqué, the twin brother of Hunahpú. [5]
| Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b / Ixbalanqué | ≥1.964±0.099 MJ | 1.26±0.12 | 433.8±2.0 | 0.079±0.040 | — | — |
References
- ^ a b c d e f g 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 c d e f Luhn, Jacob K.; et al. (2019). "Retired A Stars and Their Companions. VIII. 15 New Planetary Signals around Subgiants and Transit Parameters for California Planet Search Planets with Subgiant Hosts". The Astronomical Journal. 157 (4). 149. arXiv: 1811.03043. Bibcode: 2019AJ....157..149L. doi: 10.3847/1538-3881/aaf5d0. S2CID 102486961.
- ^ Houk, N.; Smith-Moore, M. (1988). Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars. Volume 4, Declinations -26°.0 to -12°.0. Bibcode: 1988mcts.book.....H.
- ^ a b c d Johnson, John Asher; et al. (2011). "Retired a Stars and Their Companions. VII. 18 New Jovian Planets". The Astrophysical Journal Supplement Series. 197 (2). 26. arXiv: 1108.4205. Bibcode: 2011ApJS..197...26J. doi: 10.1088/0067-0049/197/2/26.
- ^ a b "Name ExoWorlds Honduras". NameExoWorlds. IAU. Retrieved 21 December 2019.
 | This subgiant-star-related article is a stub. You can help Wikipedia by expanding it. |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Crater |
| Right ascension | 11h 17m 47.5531s [1] |
| Declination | –23° 58′ 31.4952″ [1] |
| Apparent magnitude (V) | +8.05 [2] |
| Characteristics | |
| Spectral type | K0III/IV [3] |
| Astrometry | |
| Radial velocity (Rv) | -10.30 [1] km/s |
| Proper motion (μ) |
RA: −130.770±0.068
[1]
mas/
yr Dec.: −16.887±0.050 [1] mas/ yr |
| Parallax (π) | 8.7662 ± 0.0489 mas [1] |
| Distance | 372 ± 2
ly (114.1 ± 0.6 pc) |
| Absolute magnitude (MV) | +2.6 [4] |
| Details | |
| Mass | 1.41 [2] M☉ |
| Radius | 4.6 [2] R☉ |
| Luminosity | 8.284 [1] L☉ |
| Surface gravity (log g) | 3.36 [2] cgs |
| Temperature | 4,925 [2] K |
| Age | 4 [4] Gyr |
| Database references | |
| SIMBAD | data |
HD 98219, also named Hunahpú, is a subgiant star in the constellation Crater. It has a confirmed exoplanet. At around 4 billion years old, it is a star around 1.3 times as massive as the Sun that has cooled and expanded to 4.5 times the Sun's diameter, brightening to be around 11 times as luminous. [4] The International Astronomical Union ( IAU) gave the opportunity to Honduras to name the star Hunahpú as part of NameExoWorlds. Hunahpú was one of the twin gods who became the Sun in K'iche' (Quiché) Mayan mythology. [5]
Planetary system
A gas giant planet with a minimum mass almost double that of Jupiter was discovered as part of a radial velocity survey of subgiant stars at Keck Observatory. [4] The International Astronomical Union ( IAU) has named it Ixbalanqué, the twin brother of Hunahpú. [5]
| Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b / Ixbalanqué | ≥1.964±0.099 MJ | 1.26±0.12 | 433.8±2.0 | 0.079±0.040 | — | — |
References
- ^ a b c d e f g 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 c d e f Luhn, Jacob K.; et al. (2019). "Retired A Stars and Their Companions. VIII. 15 New Planetary Signals around Subgiants and Transit Parameters for California Planet Search Planets with Subgiant Hosts". The Astronomical Journal. 157 (4). 149. arXiv: 1811.03043. Bibcode: 2019AJ....157..149L. doi: 10.3847/1538-3881/aaf5d0. S2CID 102486961.
- ^ Houk, N.; Smith-Moore, M. (1988). Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars. Volume 4, Declinations -26°.0 to -12°.0. Bibcode: 1988mcts.book.....H.
- ^ a b c d Johnson, John Asher; et al. (2011). "Retired a Stars and Their Companions. VII. 18 New Jovian Planets". The Astrophysical Journal Supplement Series. 197 (2). 26. arXiv: 1108.4205. Bibcode: 2011ApJS..197...26J. doi: 10.1088/0067-0049/197/2/26.
- ^ a b "Name ExoWorlds Honduras". NameExoWorlds. IAU. Retrieved 21 December 2019.
|
| This subgiant-star-related article is a stub. You can help Wikipedia by expanding it. |