HAT-P-17
K-type main sequence star in the constellation Cygnus
title: "HAT-P-17" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["cygnus-(constellation)", "k-type-main-sequence-stars", "planetary-systems-with-two-confirmed-planets", "planetary-transit-variables"] description: "K-type main sequence star in the constellation Cygnus" topic_path: "science/astronomy" source: "https://en.wikipedia.org/wiki/HAT-P-17" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary K-type main sequence star in the constellation Cygnus ::
| name = HAT-P-17 | epoch = J2000 | constell = Cygnus | ra = | dec = | appmag_v = 10.38 | type = main sequence | class = early K | prop_mo_ra = | prop_mo_dec = | pm_footnote = | parallax = 10.8195 | p_error = 0.0182 | parallax_footnote = | absmag_v = +5.75 | source = | mass = | radius = 0.837 | gravity = | luminosity = | temperature = | metal = | rotational_velocity = | age_gyr = | names = | Simbad = HAT-P-17
HAT-P-17 is a K-type main-sequence star about 92.4 pc away. It has a mass of about . It is the host of two planets, HAT-P-17b and HAT-P-17c, both discovered in 2010. A search for a binary companion star using adaptive optics at the MMT Observatory was negative. A candidate companion was detected by a spectroscopic search of high-resolution K band infrared spectra taken at the Keck observatory.
Planetary system
::figure[src="https://upload.wikimedia.org/wikipedia/commons/2/24/Exoplanet_Comparison_HAT-P-17_b.png" caption="Comparison of the exoplanet HAT-P-17 b with the planet Jupiter"] ::
In 2010 a multi-planet system consisting of a transiting hot Saturn in an eccentric orbit and a Jupiter like planet in an outer orbit was detected. The transiting planet HAT-P-17b was detected by the HATNet Project using telescopes located in Hawaii, Arizona and at Wise Observatory in Israel. It was confirmed with radial velocity measurements taken at the Keck telescope which also led to the discovery of the second planet on a much wider orbit.
In 2013 radial velocity measurements of the Rossiter-McLaughlin effect showed that the sky-projected angle between the stellar spin axis and the orbit of planet b was approximately 19°. The measurement in 2022 have resulted in slightly larger misalignment of 26.3°
| table_ref =
| exoplanet = b
| mass =
| semimajor =
| period =
| eccentricity =
| inclination =
| radius =
| exoplanet = c
| mass =
| semimajor =
| period =
| eccentricity =
References
References
- "HAT-P-17".
- {{Cite Gaia DR3. 1849786481032616960
- {{cite constellation. HAT-P-17
- "Open Exoplanet Catalogue - HAT-P-17 b".
- (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics.
- (2013). "Adaptive Optics Images. II. 12 Kepler Objects of Interest and 15 Confirmed Transiting Planets". The Astronomical Journal.
- (2022). "The GAPS Programme at TNG". Astronomy & Astrophysics.
- (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.
- (2013). "The Stellar Obliquity and the Long-period Planet in the HAT-P-17 Exoplanetary System". The Astrophysical Journal.
- (2012). "HAT-P-17b,c: A Transiting, Eccentric, Hot Saturn and a Long-period, Cold Jupiter". The Astrophysical Journal.
- (2015). "Friends of Hot Jupiters. III. An Infrared Spectroscopic Search for Low-mass Stellar Companions". The Astrophysical Journal.
- (2012). "Improved Spectroscopic Parameters for Transiting Planet Hosts". The Astrophysical Journal.
::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::