Astronomy:HIP 65426
280px HIP 65426 (top) and its planet (inset) seen by the James Webb Space Telescope | |
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Centaurus[1] |
| Right ascension | 13h 24m 36.09774s[2] |
| Declination | −51° 30′ 16.0447″[2] |
| Apparent magnitude (V) | 7.01[1] |
| Characteristics | |
| Evolutionary stage | main sequence |
| Spectral type | A2V[1] |
| B−V color index | 0.093[1] |
| Variable type | Delta Scuti[3] |
| Astrometry | |
| Radial velocity (Rv) | +9.77±0.71[2] km/s |
| Proper motion (μ) | RA: −33.921[2] mas/yr Dec.: −18.917[2] mas/yr |
| Parallax (π) | 9.3031 ± 0.0346[2] mas |
| Distance | 351 ± 1 ly (107.5 ± 0.4 pc) |
| Absolute magnitude (MV) | 2.06[1] |
| Details[4] | |
| Mass | 1.96±0.04 M☉ |
| Radius | 1.77±0.05 R☉ |
| Temperature | 8840±200 K |
| Rotational velocity (v sin i) | 299±9 km/s |
| Age | 14±4 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | 65426 data |
HIP 65426, also named Matza, is an A-type main-sequence star about 351 light-years (108 parsecs) away in the constellation Centaurus. With an apparent magnitude of 7.01, it is too faint to be visible to the naked eye. It hosts one known exoplanet, HIP 65426 b.
Nomenclature
The designation HIP 65426 comes from the Hipparcos catalog; other designations include HD 116434 in the Henry Draper Catalog.[5]
This was one of the 20 systems selected to be named in the third NameExoWorlds campaign, beginning in August 2022. The approved names, proposed by a team from Mexico, were announced in June 2023. The star is named Matza and its planet is named Najsakopajk; Matza means "a star in the sky" or "somebody that shines within" in the Zoque language, while Najsakopajk refers to "Mother Earth".[6]
Properties
This is a young A-type main-sequence star with a stellar classification of A2V, making it larger and hotter than the Sun. It is estimated to be about 14 million years old (for comparison, the Solar System is about 4.6 billion years old), and is a member of the Lower Centaurus-Crux association of young stars.[4] It is a Delta Scuti variable. It is a rapidly rotating star, exhibiting differential rotation with two periods of 7.85±0.08 and 6.67±0.04 hours, and is seen nearly edge-on, rotating at an inclination of 107°+12°
−11° to the plane of the sky.[3]
While it is listed in catalogs such as the Washington Double Star Catalog,[5] HIP 65426 is a single star, with no known companions other than its planet.[7] A brown dwarf designated 2MASS J13242119-5129503 was considered as a possible very distant companion, but found not to be.[7]
Planetary system
The planet HIP 65426 b, later named Najsakopajk, is a massive super-Jupiter on a wide orbit, discovered in 2017 by direct imaging.[4] It was the first exoplanet discovered by the SPHERE instrument on the Very Large Telescope,[8] and in 2022 became the first exoplanet to be imaged by the James Webb Space Telescope (JWST).[9] The planetary orbit is aligned with the host star's equator.[3]
Unlike most young planet-hosting stars, no circumstellar disk has been observed around HIP 65426.[4] JWST observations have not detected any additional planets, ruling out companions more massive than about 10 |♃|J}}}}}} at distances of 10–20 au from the star.[10]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b / Najsakopajk | 7.1±1.2 MJ | 74.6+14.9 −10.0 |
— | 0.30±0.17 | 105.2+2.5 −1.9° |
1.44±0.03 RJ |
References
- ↑ 1.0 1.1 1.2 1.3 1.4 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 2.4 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.
- ↑ 3.0 3.1 3.2 Sepulveda, Aldo G.; Huber, Daniel et al. (July 2024). "HIP 65426 is a High-frequency Delta Scuti Pulsator in Plausible Spin–Orbit Alignment with its Directly Imaged Exoplanet". The Astronomical Journal 168 (1): 13. doi:10.3847/1538-3881/ad4964. ISSN 0004-6256. Bibcode: 2024AJ....168...13S.
- ↑ 4.0 4.1 4.2 4.3 Chauvin, G.; Desidera, S. et al. (September 2017). "Discovery of a warm, dusty giant planet around HIP 65426". Astronomy & Astrophysics 605: L9. doi:10.1051/0004-6361/201731152. ISSN 0004-6361. Bibcode: 2017A&A...605L...9C.
- ↑ 5.0 5.1 5.2 "HD 116434". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+116434.
- ↑ "2022 Approved Names". IAU. https://nameexoworlds.iau.org/2022approved-names.
- ↑ 7.0 7.1 Majidi, F. Z.; Desidera, S. et al. (December 2020). "Characterization of very wide companion candidates to young stars with planets and disks". Astronomy & Astrophysics 644: A169. doi:10.1051/0004-6361/202039031. ISSN 0004-6361. Bibcode: 2020A&A...644A.169M.
- ↑ "ESO’s SPHERE Unveils its First Exoplanet". ESO. 6 July 2017. https://www.eso.org/public/announcements/ann17041/.
- ↑ Carter, Aarynn L.; Hinkley, Sasha et al. (July 2023). "The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems I: High-contrast Imaging of the Exoplanet HIP 65426 b from 2 to 16 μm". The Astrophysical Journal Letters 951 (1): L20. doi:10.3847/2041-8213/acd93e. ISSN 2041-8205. Bibcode: 2023ApJ...951L..20C.
- ↑ Ray, Shrishmoy; Sallum, Steph et al. (April 2025). "The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. III. Aperture Masking Interferometric Observations of the Star HIP 65426 at 3.8 μm". The Astrophysical Journal Letters 983 (1): L25. doi:10.3847/2041-8213/adaeb7. ISSN 2041-8205. Bibcode: 2025ApJ...983L..25R.
- ↑ Blunt, Sarah; Balmer, W. O. et al. (December 2023). "First VLTI/GRAVITY Observations of HIP 65426 b: Evidence for a Low or Moderate Orbital Eccentricity". The Astronomical Journal 166 (6): 257. doi:10.3847/1538-3881/ad06b7. ISSN 0004-6256. Bibcode: 2023AJ....166..257B.
Further reading
- Cheetham, A. C.; Samland, M. et al. (February 2019). "Spectral and orbital characterisation of the directly imaged giant planet HIP 65426 b". Astronomy & Astrophysics 622: A80. doi:10.1051/0004-6361/201834112. ISSN 0004-6361. Bibcode: 2019A&A...622A..80C.
- Petrus, S.; Bonnefoy, M. et al. (April 2021). "Medium-resolution spectrum of the exoplanet HIP 65426 b". Astronomy & Astrophysics 648: A59. doi:10.1051/0004-6361/202038914. ISSN 0004-6361. Bibcode: 2021A&A...648A..59P.
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