HD 164604
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Sagittarius[1] |
| Right ascension | Template:RA[2] |
| Declination | Template:DEC[2] |
| Apparent magnitude (V) | 9.62[1] |
| Characteristics | |
| Evolutionary stage | main sequence[3] |
| Spectral type | K3.5V(k)[4] |
| Apparent magnitude (B) | 11.016[1] |
| Apparent magnitude (J) | 7.784±0.024[1] |
| Apparent magnitude (H) | 7.306±0.038[1] |
| Apparent magnitude (K) | 7.169±0.020[1] |
| B−V color index | 1.396±0.491[1] |
| Astrometry | |
| Radial velocity (Rv) | 7.30±0.16[2] km/s |
| Proper motion (μ) | RA: −34.658[2] mas/yr Dec.: −42.253[2] mas/yr |
| Parallax (π) | 24.9867±0.0351 mas[2] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Absolute magnitude (MV) | 6.57[1] |
| Details[3] | |
| Mass | 0.77±0.02 M☉ |
| Radius | 0.78±0.02 R☉ |
| Luminosity | 0.26±0.01 L☉ |
| Surface gravity (log g) | 4.49±0.41 cgs |
| Temperature | 4,663±31 K |
| Metallicity [Fe/H] | 0.12±0.07 dex |
| Rotation | 19±3 d |
| Age | 10.7±3.8 or 1.6±0.7 Gyr |
| Other designations | |
| Template:Odlist[5] | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
HD 164604 is a single star in the southern constellation of Sagittarius. It has the proper name Pincoya, as selected in the NameExoWorlds campaign by Chile, during the 100th anniversary of the IAU. Pincoya is a female water spirit from southern Chilean mythology who is said to bring drowned sailors to the Caleuche so that they can live in the afterlife.[6][7] A 2015 survey ruled out the existence of any stellar companions at projected distances from 13 to 340 astronomical units.[8] It is known to host a single super-Jupiter exoplanet.[9]
This star is invisible to the naked eye with an apparent visual magnitude of 9.62.[1] It is located at a distance of 130.5 light-years from the Sun based on parallax, and is drifting further away with a radial velocity of +7 km/s.[2] The stellar classification of HD 164604 is K3.5V(k), which indicates this is a K-type main-sequence star. The chromosphere is considered very inactive.[4] It is roughly seven[10] billion years old with 77% of the mass and radius of the Sun. The star is radiating 26% of the luminosity of the Sun from its photosphere at an effective temperature of 4,663 K.[3]
Planetary system
A super-Jupiter exoplanet (HD 164604 b, later named Caleuche) was detected by the Magellan Planet Search Program in 2010 based on radial velocity variations of the host star.[9] The orbit of this body does not preclude a hypothetical Earth-mass exoplanet from occupying a dynamically stable orbit within the habitable zone of this star.[11] An astrometric measurement of the planet's inclination and true mass was published in 2022 as part of Gaia DR3.[12]
A second planet was found in 2026 from combined analysis of radial velocity and astrometry. This is another super-Jupiter on a wider orbit. There are two possible orbital solutions, with the outer planet's orbit being either prograde or retrograde to the inner planet's orbit. The retrograde solution is dynamically stable, while the prograde solution may be unstable. Gaia DR4 astrometry should make it possible to determine which solution is correct.[3]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination (°) |
Radius |
|---|---|---|---|---|---|---|
| b / Caleuche | 13.2+1.8 −1.5 or 8.8+1.9 −1.5 MJ |
1.362±0.012 | 653.9+1.5 −1.7 |
0.479+0.027 −0.021 |
10.6+1.4 −1.3 or 16.0+3.5 −2.8 |
— |
| c | 9.5±1.2 or 7.6±1.0 MJ |
5.556+0.093 −0.10 |
5387+120 −127 |
0.196±0.078 | 8.6+1.3 −1.0 or 169.3+1.3 −1.7 |
— |
References
- ^ a b c d e f g h i Template:Cite XHIP
- ^ a b c d e f g Template:Cite Gaia DR3
- ^ a b c d e Page Module:Citation/CS1/styles.css has no content.Xiao, Guang-Yao; Feng, Fabo; et al. (February 2026). "HD 164604 c: a second giant planet on a 15-yr orbit and the constraint of the planet-planet mutual inclination". The Astronomical Journal. arXiv:2602.10919.
- ^ a b Page Module:Citation/CS1/styles.css has no content.Gray, R. O.; et al. (July 2006). "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample". The Astronomical Journal. 132 (1): 161–170. arXiv:astro-ph/0603770. Bibcode:2006AJ....132..161G. doi:10.1086/504637. S2CID 119476992.
- ^ Page Module:Citation/CS1/styles.css has no content."HD 164604". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 5 February 2018.
{{cite web}}: Invalid|mode=Script error: No such module "Citation mode".(help) - ^ Page Module:Citation/CS1/styles.css has no content."Approved names". NameExoworlds. Retrieved 2020-01-02.
- ^ Page Module:Citation/CS1/styles.css has no content."Name Exo Worlds". www.iau.org. International Astronomical Union | IAU. Archived from the original on 2022-12-05. Retrieved 2020-01-02.
- ^ Page Module:Citation/CS1/styles.css has no content.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. Bibcode:2015MNRAS.450.3127M. doi:10.1093/mnras/stv771. hdl:1887/49340. Retrieved 19 June 2020.
- ^ a b Page Module:Citation/CS1/styles.css has no content.Arriagada, Pamela; et al. (2010). "Five Long-period Extrasolar Planets in Eccentric orbits from the Magellan Planet Search Program". The Astrophysical Journal. 711 (2): 1229–35. arXiv:1001.4093. Bibcode:2010ApJ...711.1229A. doi:10.1088/0004-637X/711/2/1229. S2CID 118682009.
- ^ Page Module:Citation/CS1/styles.css has no content.Pace, G. (March 2013), "Chromospheric activity as age indicator. An L-shaped chromospheric-activity versus age diagram", Astronomy & Astrophysics, 551: 4, arXiv:1301.5651, Bibcode:2013A&A...551L...8P, doi:10.1051/0004-6361/201220364, S2CID 56420519, L8.
- ^ Page Module:Citation/CS1/styles.css has no content.Agnew, Matthew T.; et al. (November 2017). "Stable habitable zones of single Jovian planet systems". Monthly Notices of the Royal Astronomical Society. 471 (4): 4494–4507. arXiv:1706.05805. Bibcode:2017MNRAS.471.4494A. doi:10.1093/mnras/stx1449.
- ^ Page Module:Citation/CS1/styles.css has no content.Gaia Collaboration; et al. (2023). "Gaia Data Release 3". Astronomy & Astrophysics. 674: A34. arXiv:2206.05595. doi:10.1051/0004-6361/202243782. S2CID 249626026.
Further reading
- Page Module:Citation/CS1/styles.css has no content.Feng, Fabo; et al. (June 2019). "Search for Nearby Earth Analogs. I. 15 Planet Candidates Found in PFS Data". The Astrophysical Journal Supplement Series. 242 (2): 31. arXiv:1904.08567. Bibcode:2019ApJS..242...25F. doi:10.3847/1538-4365/ab1b16. S2CID 121128472. 25.
