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]
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] |
Distance | 344 ± 4 ly (105 ± 1 pc) |
Orbit[2][4] | |
Primary | BD-07 436A |
Companion | BD-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 | |
Mass | 0.903+0.066 −0.059 M☉ |
Radius | 0.910+0.025 −0.023 R☉ |
Luminosity | 0.743+0.065 −0.058 L☉ |
Surface gravity (log g) | 4.476+0.014 −0.015 cgs |
Temperature | 5617±72 K |
Metallicity [Fe/H] | −0.10+0.10 −0.11 dex |
Rotation | 15.4±0.5[6] |
Rotational velocity (v sin i) | 4.0±0.2 km/s |
Age | 5[2] Gyr |
BD-07 436B | |
Mass | 0.71±0.06[7] M☉ |
Radius | 0.69±0.12[7] R☉ |
Surface gravity (log g) | 4.6±0.15[7] cgs |
Temperature | 5570±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 | |
Database references | |
SIMBAD | 436 data |
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
editIn 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]
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
edit- ^ a b c d e "BD-07 436". SIMBAD. Centre de données astronomiques de Strasbourg.
- ^ 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
- ^ 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 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
- ^ 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
- ^ 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
- ^ 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
- ^ 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
- ^ 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
- ^ 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