Astronomy:HAT-P-7

From HandWiki

HAT-P-7 is a triple star system located about 1,088 light-years away in the constellation Cygnus. The apparent magnitude of this star is 10.5, which means it is not visible to the naked eye but can be seen with a small telescope on a clear dark night.[1]

Stellar system

The primary component of the HAT-P-7 system is an F-type main-sequence star with around 1.35 times the Sun's mass and twice the Sun's radius, hosting one known planet. The secondary is a red dwarf located 730 astronomical units away from the primary, with a spectral type of M5.5V and a mass of 0.21 M☉. The tertiary is also a red dwarf with a mass of at least 0.15 M☉; it is in a highly-eccentric orbit with a semi-major axis of 32 AU.[2]

The secondary star, component B, was discovered in 2012. Another companion (in addition to the second star and the planet) was suspected based on long-period radial velocity variations,[3] but its nature was unknown until 2025, when it was found to be a third star.[2]

Component B has also been referred to as HAT-P-7 East. HAT-P-7 West is another candidate companion, of spectral type M9V or L0V, but it is not confirmed to be associated with the system and is likely an unrelated background star.[4][3]

Planetary system

The primary star has one known planet, HAT-P-7b, a hot Jupiter discovered in 2008. This star system was within the initial field of view of the Kepler planet-hunting spacecraft[5] and was given the designation KOI-2 and later Kepler-2.

The HAT-P-7 planetary system[6]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
b 1.806±0.036 MJ 0.03813±0.00036 2.20473539167(1654)[7] <0.0040 83.151+0.030
−0.033° 		1.51±0.02 RJ

See also

References

  1. ↑ "HAT-P-7". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HAT-P-7. 
  2. ↑ 2.0 2.1 Yang, Eritas; Su, Yubo; Winn, Joshua N. (2025-05-12). "A third star in the HAT-P-7 system, and a new dynamical pathway to misaligned hot Jupiters". The Astrophysical Journal 986 (2): 117. doi:10.3847/1538-4357/add5f7. Bibcode: 2025ApJ...986..117Y. 
  3. ↑ 3.0 3.1 Narita, Norio et al. (December 2012). "A Common Proper Motion Stellar Companion to HAT-P-7". Publications of the Astronomical Society of Japan 64 (6): L7. doi:10.1093/pasj/64.6.L7. Bibcode: 2012PASJ...64L...7N. 
  4. ↑ Narita, Norio et al. (2010). "Search for Outer Massive Bodies around Transiting Planetary Systems: Candidates of Faint Stellar Companions around HAT-P-7". Publications of the Astronomical Society of Japan 62 (3): 779. doi:10.1093/pasj/62.3.779. Bibcode: 2010PASJ...62..779N. 
  5. ↑ Pál, A. et al. (2008). "HAT-P-7b: An Extremely Hot Massive Planet Transiting a Bright Star in the Kepler Field". The Astrophysical Journal 680 (2): 1450–1456. doi:10.1086/588010. Bibcode: 2008ApJ...680.1450P. 
  6. ↑ Bonomo, A. S. et al. (2017). "The GAPS Programme with HARPS-N at TNG . XIV. Investigating giant planet migration history via improved eccentricity and mass determination for 231 transiting planets". Astronomy and Astrophysics 602: A107. doi:10.1051/0004-6361/201629882. Bibcode: 2017A&A...602A.107B. 
  7. ↑ Battley, Matthew P et al. (10 March 2021). "Revisiting the Kepler field with TESS: Improved ephemerides using TESS 2 min data". Monthly Notices of the Royal Astronomical Society 503 (3): 4092–4104. doi:10.1093/mnras/stab701. Bibcode: 2021MNRAS.503.4092B. 

Cite error: <ref> tag with name "constellation" defined in <references> is not used in prior text.
Cite error: <ref> tag with name "Gaia DR3" defined in <references> is not used in prior text.
Cite error: <ref> tag with name "Torres2012" defined in <references> is not used in prior text.
Cite error: <ref> tag with name "tic" defined in <references> is not used in prior text.

Cite error: <ref> tag with name "Faedi2013" defined in <references> is not used in prior text.

Further reading

Coordinates: Sky map 19h 28m 59s, +47° 58′ 10″



Retrieved from "https://handwiki.org/wiki/index.php?title=Astronomy:HAT-P-7&oldid=4132803"