BD−07 436

BD−07°436
Observation data
Epoch J2000      Equinox ICRS
Constellation Cetus
A
Right ascension 02h 28m 37.228s
Declination −07° 03′ 38.38″
Apparent magnitude (V) 10.29
B
Right ascension 02h 28m 37.324s
Declination −07° 03′ 41.28″
Apparent magnitude (V) 13.4
Characteristics
A
Evolutionary stage main-sequence star
Spectral type G8V
B
Evolutionary stage main-sequence star
Spectral type K5
Astrometry
A
Radial velocity (Rv)+1.44±0.17 km/s
Proper motion (μ) RA: +93.708 mas/yr
Dec.: −1.717 mas/yr
Parallax (π)9.4629±0.0183 mas
Distance344.7 ± 0.7 ly
(105.7 ± 0.2 pc)
B
Radial velocity (Rv)+3.22±1.63 km/s
Proper motion (μ) RA: +94.240 mas/yr
Dec.: −3.787 mas/yr
Parallax (π)9.5080±0.0183 mas
Distance343.0 ± 0.7 ly
(105.2 ± 0.2 pc)
Absolute magnitude (MV)7.2
Orbit
PrimaryBD−07 436A
SecondaryBD−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
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)4.42±0.03 cgs
Temperature5615±9 K
Metallicity [Fe/H]−0.10+0.10
−0.11 dex
Rotation15.4±0.5
Rotational velocity (v sin i)4.0±0.2 km/s
Age7.99+1.90
−1.71 Gyr
BD−07 436B
Mass0.71±0.06 M☉
Radius0.69±0.12 R☉
Surface gravity (log g)4.6±0.15 cgs
Temperature5570±240 K
Metallicity [Fe/H]-0.11±0.19 dex
Rotational velocity (v sin i)2.8±0.5 km/s
Age7.3+4.4
−4.6 Gyr
Other designations
WASP-77, 2MASS J02283722-0703384
A: TOI-398, TIC 1129033, TYC 4697-201-1
B: TIC 632613066
Database references
SIMBADdata
A
B

BD−07 436, also known as WASP-77 since 2012, is a binary star system about 344 light-years away. 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.

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. The secondary is a K-type main-sequence star BD−07 436B orbiting at a distance of 461+200
−140 AU.

When calculated using spin rates, the two components appear to have different ages, with the secondary one billion years old, while the primary's age is 0.4 billion years. When calculated from X-ray luminosity, the ages are radically different and even more inconsistent at 4.5 and >8.9 billion years respectively. These ages may be unreliable, with the spin rates and X-ray luminosities affected by binary evolution, and ages inferred from the stars' positions in the H-R diagram are 7.99 and 7.3 billion years respectively.

Planetary system

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

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

The BD−07 436A planetary system
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. ↑ Roman, Nancy G. (1987). "Identification of a constellation from a position". Publications of the Astronomical Society of the Pacific. 99 (617): 695. Bibcode:1987PASP...99..695R. doi:10.1086/132034. Constellation record for this object at VizieR.
  2. 1 2 3 4 5 6 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  3. 1 2 Trifonov, Trifon; Tal-Or, Lev; Zechmeister, Mathias; Kaminski, Adrian; Zucker, Shay; Mazeh, Tsevi (2020). "Public HARPS radial velocity database corrected for systematic errors". Astronomy and Astrophysics. 636: A74. arXiv:2001.05942. Bibcode:2020A&A...636A..74T. doi:10.1051/0004-6361/201936686.
  4. 1 2 3 4 5 6 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  5. 1 2 3 4 5 6 7 8 9 10 11 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
  6. 1 2 3 4 5 6 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
  7. 1 2 3 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
  8. 1 2 3 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
  9. 1 2 Sun, Qinghui; Tan, Xianyu; Gordon; Yip; Lin, Zitao; Liu, Fan; Wang, Sharon Xuesong; Li, Zhengduo (2026-04-20). "JWST Exoplanetary Worlds and Elemental Survey (JEWELS) II: Condensation Temperature Trends and Galactic Chemical Evolution in JWST Planet-Hosting Stars". The Astrophysical Journal Supplement Series. arXiv:2604.18115.
  10. 1 2 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
  11. 1 2 3 Reggiani, Henrique; Schlaufman, Kevin C.; Healy, Brian F.; Lothringer, Joshua D.; Sing, David K. (2022). "Evidence that the Hot Jupiter WASP-77 a b Formed Beyond Its Parent Protoplanetary Disk's H2O Ice Line". The Astronomical Journal. 163 (4): 159. arXiv:2201.08508. Bibcode:2022AJ....163..159R. doi:10.3847/1538-3881/ac4d9f.
  12. ↑ "BD−07 436". SIMBAD. Centre de données astronomiques de Strasbourg.
  13. ↑ 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
  14. ↑ 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
  15. ↑ 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