HAT-P-7

{{Starbox begin

| name = HAT-P-7

}}

{{Starbox observe

| epoch = J2000

| constell = Cygnus

| ra = {{RA|19|28|59.3539}}

| dec = {{DEC|+47|58|10.217}}

| appmag_v = 10.46

}}

{{Starbox character

| component1 = A

| type = Main sequence

| class = F6V

| appmag_1_passband = B

| appmag_1 = ~10.90

| appmag_2_passband = V

| appmag_2 = ~10.46

| appmag_3_passband = J

| appmag_3 = 9.555 ± 0.030

| appmag_4_passband = H

| appmag_4 = 9.344 ± 0.029

| appmag_5_passband = K

| appmag_5 = 9.334 ± 0.018

| variable = planetary transit

| component2 = B

| type2 = Main sequence

| class2 = M5.5V

}}

{{Starbox astrometry

| radial_v = {{val|-10.23|0.25}}

| prop_mo_ra = {{val|−18.325|(14)}}

| prop_mo_dec = {{val|8.851|(14)}}

| pm_footnote =

| parallax = 2.9991

| p_error = 0.0114

| parallax_footnote =

| absmag_v =

}}

{{Starbox orbit

| reference =

| primary = A

| name = B

| axis_unitless = 730 AU

}}

{{Starbox orbit

| reference =

| primary = A

| name = C

| axis_unitless = {{val|32|16|11}} AU

| eccentricity = {{Val|0.76|0.12|0.26}}

}}

{{Starbox detail

| source =

| component1 = A

| mass = {{Val|1.35|0.22}}

| radius = {{Val|1.994|0.081}}

| luminosity =

| gravity = {{Val|3.97|0.08}}

| temperature = {{Val|fmt=commas|6532|109}}

| metal_fe = {{Val|0.15|0.08}}

| rotational_velocity = {{Val|5.0|1.2}}

| age_gyr =

}}

{{Starbox detail|no_heading=y

| component1 = B

| mass = 0.21

| component2 = C

| mass2 = 0.19

}}

{{Starbox catalog

| names = HAT-P-7, {{odlist | BD=+47°2846 | 2MASS=J19285935+4758102 | GSC=03547-01402 | Kepler=2 | KIC=10666592 | KOI=2 | TIC=424865156 | TOI=1265 | TYC=3547-1402-1 }}

}}

{{Starbox reference

| Simbad = GSC03547-01402

| NSTED = HAT-P-7

}}

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.

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 {{solar mass|0.21}}. The tertiary is also a red dwarf with a mass of at least {{solar mass|0.15}}; it is in a highly-eccentric orbit with a semi-major axis of 32 AU.

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, but its nature was unknown until 2025, when it was found to be a third star.

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.

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 and was given the designation KOI-2 and later Kepler-2.

{{OrbitboxPlanet begin

| table_ref =

}}

{{OrbitboxPlanet

| exoplanet = b

| mass = {{val|1.806|0.036}}

| period = {{val|2.20473539167|(1654)}}

| semimajor = {{val|0.03813|0.00036}}

| eccentricity = {{val|0.0040|p=<}}

| inclination = {{val|83.151|0.030|0.033}}

| radius = {{val|1.51|0.02}}

}}

References

{{Reflist|refs=

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{{cite journal |bibcode=2010PASJ...62..779N |title=Search for Outer Massive Bodies around Transiting Planetary Systems: Candidates of Faint Stellar Companions around HAT-P-7 |last1=Narita |first1=Norio |last2=Kudo |first2=Tomoyuki |last3=Bergfors |first3=Carolina |last4=Nagasawa |first4=Makiko |last5=Thalmann |first5=Christian |last6=Sato |first6=Bun'ei |last7=Suzuki |first7=Ryuji |last8=Kandori |first8=Ryo |last9=Janson |first9=Markus |last10=Goto |first10=Miwa |last11=Brandner |first11=Wolfgang |last12=Ida |first12=Shigeru |last13=Abe |first13=Lyu |last14=Carson |first14=Joseph |last15=Egner |first15=Sebastian E. |last16=Feldt |first16=Markus |last17=Golota |first17=Taras |last18=Guyon |first18=Olivier |last19=Hashimoto |first19=Jun |last20=Hayano |first20=Yutaka |last21=Hayashi |first21=Masahiko |last22=Hayashi |first22=Saeko S. |last23=Henning |first23=Thomas |last24=Hodapp |first24=Klaus W. |last25=Ishii |first25=Miki |last26=Knapp |first26=Gillian R. |last27=Kusakabe |first27=Nobuhiko |last28=Kuzuhara |first28=Masayuki |last29=Matsuo |first29=Taro |last30=McElwain |first30=Michael W. |journal=Publications of the Astronomical Society of Japan |date=2010 |volume=62 |issue=3 |page=779 |doi=10.1093/pasj/62.3.779 |arxiv=1004.2458 |display-authors=1 }}

{{cite journal |last1=Narita |first1=Norio |last2=Takahashi |first2=Yasuhiro H. |display-authors=etal |date=December 2012 |title=A Common Proper Motion Stellar Companion to HAT-P-7 |journal=Publications of the Astronomical Society of Japan |volume=64 |issue=6 |pages=L7 |doi=10.1093/pasj/64.6.L7 |arxiv=1209.4422 |bibcode=2012PASJ...64L...7N}}

{{Cite journal |last1=Yang |first1=Eritas |last2=Su |first2=Yubo |last3=Winn |first3=Joshua N. |title=A third star in the HAT-P-7 system, and a new dynamical pathway to misaligned hot Jupiters |journal=The Astrophysical Journal |date=2025-05-12 |volume=986 |issue=2 |page=117 |doi=10.3847/1538-4357/add5f7 |doi-access=free |arxiv=2505.07927|bibcode=2025ApJ...986..117Y }}

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{{Cite journal |last1=Stassun |first1=Keivan G. |last2=Oelkers |first2=Ryan J. |last3=Paegert |first3=Martin |last4=Torres |first4=Guillermo |last5=Pepper |first5=Joshua |last6=De Lee |first6=Nathan |last7=Collins |first7=Kevin |last8=Latham |first8=David W. |last9=Muirhead |first9=Philip S. |last10=Chittidi |first10=Jay |last11=Rojas-Ayala |first11=Bárbara |last12=Fleming |first12=Scott W. |last13=Rose |first13=Mark E. |last14=Tenenbaum |first14=Peter |last15=Ting |first15=Eric B. |date=2019-10-01 |title=The Revised TESS Input Catalog and Candidate Target List |journal=The Astronomical Journal |volume=158 |issue=4 |pages=138 |doi=10.3847/1538-3881/ab3467 |doi-access=free |arxiv=1905.10694 |bibcode=2019AJ....158..138S |issn=0004-6256}}

{{cite journal | title=Lucky imaging of transiting planet host stars with LuckyCam | last1=Faedi | first1=F. | last2=Staley | first2=T. | last3=Gómez Maqueo Chew | first3=Y. | last4=Pollacco | first4=D. | last5=Dhital | first5=S. | last6=Barros | first6=S. C. C. | last7=Skillen | first7=I. | last8=Hebb | first8=L. | last9=Mackay | first9=C. | last10=Watson | first10=C. A. | display-authors=1 | journal=Monthly Notices of the Royal Astronomical Society | year=2013 | volume=433 | issue=3 | pages=2097–2106 | arxiv=1305.3795 | bibcode=2013MNRAS.433.2097F | bibcode-access=free | doi=10.1093/mnras/stt885 | doi-access=free }}

}}