HD 142245

Triple star system in the constellation Serpens

HD 142245
Observation data Epoch J2000 Equinox J2000
Constellation	Serpens
Right ascension	15^h 52^m 56.2803^s^[1]
Declination	+15° 25′ 50.5399″^[1]
Apparent magnitude (V)	7.45
Characteristics
Evolutionary stage	subgiant
Spectral type	K0IV+M1^[2]
Astrometry

Radial velocity (R_v)	6.92 km/s
Proper motion (μ)	RA: -57.477 mas/yr Dec.: -21.764 mas/yr
Parallax (π)	10.2562 ± 0.0411 mas^[3]
Distance	318 ± 1 ly (97.5 ± 0.4 pc)

Orbit
Primary	HD 142245 A
Companion	HD 142245 BC
Semi-major axis (a)	2.5" (237 AU^[4])
Details^[5]
HD 142245 A
Mass	1.52±0.05^[2] `M`_☉
Radius	4.8±0.1^[6] `R`_☉
Luminosity	11.4^[6] `L`_☉
Surface gravity (log g)	3.21±0.14 cgs
Temperature	4838±36^[7] K
Metallicity	0.20±0.02^[7]
Age	2.855±0.514 Gyr
HD 142245 BC
Mass	0.56^[4] `M`_☉
Other designations
BD+15 2925, Gaia DR2 1193193836691820032, HD 142245, HIP 77783, TYC 1496-1841-1, 2MASS J15525629+1525507^[1]
Database references
SIMBAD	data

HD 142245 is a hierarchical triple star system about 318 light-years away.

The primary subgiant star HD 142245 A belongs to the spectral class of K0. Its age is much younger than Sun`s at 2.855±0.514 billion years.^[7] The primary star is slightly enriched by heavy elements, having 160% of solar abundance.^[7]

In 2014, the co-moving binary stellar companion HD 142245 BC was detected. It consists of pair of red dwarf stars with composite spectral class M1, orbiting each other on 4 AU orbit.^[4]

No other stellar companions were found at projected separations from 5.48 to 153.34 AU around HD 142245 A.^[2]

Planetary system

In 2011 one superjovian planet HD 142245 A b on a mildly eccentric orbit around star HD 142245 A was discovered utilizing the radial velocity method.^[8]

The HD 142245 planetary system^[9]
Companion (in order from star)	Mass	Semimajor axis (AU)	Orbital period (days)	Eccentricity	Inclination	Radius
HD 142245 A b	≥1.9±0.2 M_J	2.77±0.09	1299±48	0.32	—	—

References

^ ^a ^b ^c "HD 142245". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 13 October 2020.
^ ^a ^b ^c Wittrock, Justin M.; Kane, Stephen R.; Horch, Elliott P.; Howell, Steve B.; Ciardi, David R.; Everett, Mark E. (2017), "Exclusion of Stellar Companions to Exoplanet Host Stars", The Astronomical Journal, 154 (5): 184, arXiv:1709.05315, Bibcode:2017AJ....154..184W, doi:10.3847/1538-3881/aa8d69, S2CID 55789971
^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
^ ^a ^b ^c M. Mugrauer, C. Ginski, "High-contrast imaging search for stellar and substellar companions of exoplanet host stars", 2014
^ Sousa, S. G.; Adibekyan, V.; Delgado-Mena, E.; Santos, N. C.; Andreasen, D. T.; Ferreira, A. C. S.; Tsantaki, M.; Barros, S. C. C.; Demangeon, O.; Israelian, G.; Faria, J. P.; Figueira, P.; Mortier, A.; Brandao, I.; Montalto, M.; Rojas-Ayala, B.; Santerne, A. (2018), "SWEET-Cat updated New homogenous spectroscopic parameters", Astronomy & Astrophysics, A58: 620, arXiv:1810.08108, Bibcode:2018A&A...620A..58S, doi:10.1051/0004-6361/201833350, S2CID 119374557
^ ^a ^b Bonfanti, A.; Ortolani, S.; Piotto, G.; Nascimbeni, V. (2015), "Revising the ages of planet-hosting stars", Astronomy & Astrophysics, 575: A18, arXiv:1411.4302, Bibcode:2015A&A...575A..18B, doi:10.1051/0004-6361/201424951, S2CID 54555839
^ ^a ^b ^c ^d Ghezzi, Luan; Montet, Benjamin T.; Johnson, John Asher (2018), "Retired a Stars Revisited: An Updated Giant Planet Occurrence Rate as a Function of Stellar Metallicity and Mass", The Astrophysical Journal, 860 (2): 109, arXiv:1804.09082, Bibcode:2018ApJ...860..109G, doi:10.3847/1538-4357/aac37c, S2CID 118969017
^ John Asher Johnson; Clanton, Christian; Howard, Andrew W.; Bowler, Brendan P.; Henry, Gregory W.; Marcy, Geoffrey W.; Crepp, Justin R.; Endl, Michael; Cochran, William D.; MacQueen, Phillip J.; Wright, Jason T.; Isaacson, Howard (2011), "Retired a Stars and Their Companions. Vii. 18 New Jovian Planets", The Astrophysical Journal Supplement Series, 197 (2): 26, arXiv:1108.4205, Bibcode:2011ApJS..197...26J, doi:10.1088/0067-0049/197/2/26, S2CID 15088371
^ Planet HD 142245 A b on exoplanet.eu

Constellation of Serpens

Stars

Bayer	α (Unukalhai) β (Chow) γ (Ainalhai) δ ε ζ η θ (Alya) ι κ (Gudja) λ μ ν ξ ο π ρ σ τ¹ τ² τ³ τ⁴ τ⁵ τ⁶ τ⁷ τ⁸ υ φ χ ψ ω
Flamsteed	3 4 5 6 7 8 10 11 (A¹) 14 16 25 (A²) 29 36 (b) 39 40 43 45 46 47 59 (d) 60 (c) 61 64 3 Her 47 Oph
Variable	R W X RT UZ VV VY WX AA AN AO AP AR AU BQ CT CV CW EG FH FI FK FL FQ FR LV LW LX MR MS MT MV MY NN NO NQ NW OO OU PS QV QX QY V382 V411
HR	5665 5690 5692 5706 5711 5740 5745 5783 5796 5831 5850 5859 5861 5874 5909 5913 5931 5992 6005 6011 6014 6016 6449 6496 6544 6562 6568 6600 6620 6666 6681 6755 6756 6757 6785 6830 6840 6843 6858 6890 6898 6928 6993 (e) 6999 7008 7048 7076 7144
HD	135061 135615 136027 136118 138085 142245 143436 145936 146740 157969 168112 168443 168746 (Alasia) 175541 (Kaveh)
Other	ADS 9544 AS 296 9 11 22 23 27 Gliese 701 Gliese 710 GJ 1224 GX 17+2 IRAS 18418-0440 MWC 297 MWC 922 PG 1510+234 PG 1605+072 PSR B1534+11 PSR J1719−1438 Ross 508 Serpens FIRS 1 Serpens SVS 20 Serpens X-1 W40 IRS 1A South

Exoplanets	CoRoT-9b CoRoT-11b CoRoT-22b CoRoT-23b CoRoT-27b HD 168746 b (Onasilos) HD 175541 b (Kavian) ω Serpentis b

Star
clusters

NGC	NGC 6535 NGC 6539 NGC 6604 NGC 6605
Other	IC 4756 Messier 5 Messier 16 Serpens OB2 Serpens South Palomar 5

Nebulae

Other	Abell 41 Eagle Nebula L134 L183 L483 Serpens cloud Sh2-54 Westerhout 40 Red Square Nebula S68

Galaxies

NGC	5887 5910 5911 5913 5919 5920 5921 5926 5928 5931 5936 5937 5940 5942 5941 5944 5951 5953 5954 5952 5956 5955 5957 5960 5962 5964 5970 5972 5975 5977 5980 5983 5984 5988 5991 5990 5994 5996 5997 6003 6004 6008 6006 6007 6009 6012 6010 6014 6020 6017 6018 6021 6022 6023 6027 6027a 6027b 6027c 6027d 6027e 6029 6033 6037 6036 6051 6063 6065 6066 6070 6080 6100 6118 6172
Other	317 318 321 323.1 324 326 Arp 72 Arp 220 4C 11.50 CGCG 049-033 Hoag's Object IC 4537 IC 4588 IRAS 15107+0724 NRAO 530 PDS 456 PG 1553+113 PGC 54493 PKS 1546+027

NGC