BD-07 436
Observation data
Epoch J2000      Equinox J2000
Constellation Cetus
Right ascension 02h 28m 37.226s[1]
Declination −07° 03′ 38.39″[1]
Apparent magnitude (V) 10.12
Characteristics
Evolutionary stage main-sequence star
Spectral type G8+K5[2]
Astrometry
Proper motion (μ) RA: 88[1] mas/yr
Dec.: 8.1[1] mas/yr
Parallax (π)9.4818 ± 0.1073 mas[3]
Distance344 ± 4 ly
(105 ± 1 pc)
Orbit[2][4]
PrimaryBD-07 436A
CompanionBD-07 436B
Semi-major axis (a)3.3"
(461+200
−140 AU)
Eccentricity (e)0.51+0.26
−0.22
Inclination (i)77+5
−7°
Details[5]
BD-07 436A
Mass0.903+0.066
−0.059 M☉
Radius0.910+0.025
−0.023 R☉
Luminosity0.743+0.065
−0.058 L☉
Surface gravity (log g)4.476+0.014
−0.015 cgs
Temperature5617±72 K
Metallicity [Fe/H]−0.10+0.10
−0.11 dex
Rotation15.4±0.5[6]
Rotational velocity (v sin i)4.0±0.2 km/s
Age5[2] Gyr
BD-07 436B
Mass0.71±0.06[7] M☉
Radius0.69±0.12[7] R☉
Surface gravity (log g)4.6±0.15[7] cgs
Temperature5570±240[4] K
Metallicity [Fe/H]-0.11±0.19[7] dex
Rotational velocity (v sin i)2.8±0.5[7] km/s
Age>9[2] Gyr
Other designations
Gaia DR2 5178405479960844160, TOI-398, WASP-77, TYC 4697-201-1, 2MASS J02283722-0703384[1]
Database references
SIMBAD436 data

BD-07 436, also known as WASP-77 since 2012,[7] is a binary star system about 344 light-years away. The star's components appears to have a different age, with the secondary older than 9 billion years, while the primary's age is 5 billion years.[2] The BD-07 436 system's concentration of heavy elements is similar to the Sun. Its stars display moderate chromospheric activity, including x-ray flares.[2]

The primary is a G-type main-sequence star, BD-07 436A (WASP-77A). The star is rotating rapidly, being spun up by the tides raised by the giant planet WASP-77Ab on its close orbit.[6] The secondary is a K-type main-sequence star BD-07 436B orbiting at a distance of 461+200
−140 AU.[4]

Planetary system

In 2012 a transiting hot Jupiter planet b was detected on a very tight, circular orbit.[7] The planet may have an extended gaseous envelope and is losing mass.[2] Its equilibrium temperature is 1715+26
−25 K,[5]the nightside temperature measured in 2019 is 1786±84 K,[8] and dayside planetary temperature measured in 2020 is 1842+34
−33 K.[9]

Water vapour was detected on the planetary dayside of WASP-77Ab, indicating C/O ratio similar to solar or even lower.[10]

The BD-07 436A planetary system[5]
Companion
(in order from star) 		Mass Semimajor axis
(AU) 		Orbital period
(days) 		Eccentricity Inclination Radius
Ab 1.667+0.068
−0.064 MJ 		0.02335+0.00045
−0.00043 		1.36002854±0.00000062 0.0074+0.0069
−0.0049 		88.91+0.74
−0.95° 		1.230+0.031
−0.029 RJ

References

  1. ^ a b c d e "BD-07 436". SIMBAD. Centre de données astronomiques de Strasbourg.
  2. ^ a b c d e f g Salz, M.; Schneider, P. C.; Czesla, S.; Schmitt, J. H. M. M. (2015), "High-energy irradiation and mass loss rates of hot Jupiters in the solar neighborhood", Astronomy & Astrophysics, 576: A42, arXiv:1502.00576, Bibcode:2015A&A...576A..42S, doi:10.1051/0004-6361/201425243, S2CID 55139248
  3. ^ 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.
  4. ^ a b c Evans, D. F.; Southworth, J.; Smalley, B.; Jørgensen, U. G.; Dominik, M.; Andersen, M. I.; Bozza, V.; Bramich, D. M.; Burgdorf, M. J.; Ciceri, S.; d'Ago, G.; Figuera Jaimes, R.; Gu, S.-H.; Hinse, T. C.; Henning, Th.; Hundertmark, M.; Kains, N.; Kerins, E.; Korhonen, H.; Kokotanekova, R.; Kuffmeier, M.; Longa-Peña, P.; Mancini, L.; MacKenzie, J.; Popovas, A.; Rabus, M.; Rahvar, S.; Sajadian, S.; Snodgrass, C.; et al. (2018), "High-resolution Imaging of Transiting Extrasolar Planetary systems (HITEP). II. Lucky Imaging results from 2015 and 2016", Astronomy & Astrophysics, 610: A20, arXiv:1709.07476, Bibcode:2018A&A...610A..20E, doi:10.1051/0004-6361/201731855, S2CID 53400492
  5. ^ a b c Cortes-Zuleta, Pia; Rojo, Patricio; Wang, Songhu; Hinse, Tobias C.; Hoyer, Sergio; Sanhueza, Bastian; Correa-Amaro, Patricio; Albornoz, Julio (2020), "TraMoS V. Updated ephemeris and multi-epoch monitoring of the hot Jupiters WASP-18Ab, WASP-19b, and WASP-77Ab", Astronomy & Astrophysics, A98: 636, arXiv:2001.11112, Bibcode:2020A&A...636A..98C, doi:10.1051/0004-6361/201936279, S2CID 210966021
  6. ^ a b Gallet, F.; Gallet (2020), "TATOO: Tidal-chronology standalone tool to estimate the age of massive close-in planetary systems", Astronomy & Astrophysics, 641: A38, arXiv:2006.07880, Bibcode:2020A&A...641A..38G, doi:10.1051/0004-6361/202038058, S2CID 219687851
  7. ^ a b c d e f g Maxted, P. F. L.; Anderson, D. R.; Collier Cameron, A.; Doyle, A. P.; Fumel, A.; Gillon, M.; Hellier, C.; Jehin, E.; Lendl, M.; Pepe, F.; Pollacco, D. L.; Queloz, D.; Ségransan, D.; Smalley, B.; Southworth, K.; Smith, A. M. S.; Triaud, A. H. M. J.; Udry, S.; West, R. G. (2012), "WASP-77 Ab: A transiting hot Jupiter planet in a wide binary system", Publications of the Astronomical Society of the Pacific, 125 (923): 48–55, arXiv:1211.6033, doi:10.1086/669231, S2CID 53552999
  8. ^ Garhart, Emily; Deming, Drake; Mandell, Avi; Knutson, Heather A.; Wallack, Nicole; Burrows, Adam; Fortney, Jonathan J.; Hood, Callie; Seay, Christopher; Sing, David K.; Benneke, Björn; Fraine, Jonathan D.; Kataria, Tiffany; Lewis, Nikole; Madhusudhan, Nikku; McCullough, Peter; Stevenson, Kevin B.; Wakeford, Hannah (2020), "Statistical Characterization of Hot Jupiter Atmospheres Using Spitzer's Secondary Eclipses", The Astronomical Journal, 159 (4): 137, arXiv:1901.07040, Bibcode:2020AJ....159..137G, doi:10.3847/1538-3881/ab6cff, S2CID 119209434
  9. ^ Wong, Ian; Shporer, Avi; Daylan, Tansu; Benneke, Björn; Fetherolf, Tara; Kane, Stephen R.; Ricker, George R.; Vanderspek, Roland; Latham, David W.; Winn, Joshua N.; Jenkins, Jon M.; Boyd, Patricia T.; Glidden, Ana; Goeke, Robert F.; Sha, Lizhou; Ting, Eric B.; Yahalomi, Daniel (2020), "Systematic phase curve study of known transiting systems from year one of the TESS mission", The Astronomical Journal, 160 (4): 155, arXiv:2003.06407, Bibcode:2020AJ....160..155W, doi:10.3847/1538-3881/ababad, S2CID 212717799
  10. ^ Mansfield, Megan; Wiser, Lindsey; Stevenson, Kevin B.; Smith, Peter; Line, Michael R.; Bean, Jacob L.; Fortney, Jonathan J.; Parmentier, Vivien; Kempton, Eliza M.-R.; Arcangeli, Jacob; Désert, Jean-Michel; Kilpatrick, Brian; Kreidberg, Laura; Malik, Matej (2022), "Confirmation of Water Absorption in the Thermal Emission Spectrum of the Hot Jupiter WASP-77Ab with HST/WFC3", The Astronomical Journal, 163 (6): 261, arXiv:2203.01463, Bibcode:2022AJ....163..261M, doi:10.3847/1538-3881/ac658f, S2CID 247223194



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