View source for Astronomy:BD-07 436

{{Short description|Star in the constellation Cetus}}
{{Starbox begin
| name = BD-07 436
}}
{{Starbox observe
| epoch = J2000
| ra = {{RA|02|28|37.226}}<ref name=simbad/>
| dec = {{DEC|-07|03|38.39}}<ref name=simbad/>
| constell = [[Astronomy:Cetus|Cetus]]
| appmag_v = 10.12
}}
{{Starbox character
| type=main-sequence star
| class = G8+K5<ref name=Salz2015/>
}}
{{Starbox astrometry
| radial_v = 
| prop_mo_ra = 88<ref name=simbad/>
| prop_mo_dec = 8.1<ref name=simbad/>
| parallax = 9.4818
| p_error = 0.1073
| parallax_footnote = <ref name=dr2>{{cite DR2|5178405479960844160}}</ref>
}}
{{Starbox orbit
| reference = <ref name=Salz2015/><ref name=Evans2017/>
| primary = BD-07 436A
| name = BD-07 436B
| period = <!--Period (in years)-->
| period_unitless = <!--Period (no units provided by template)-->
| axis = 3.3
| axis_unitless = 461{{±|200|140}} [[Astronomy:Astronomical unit|AU]]
| eccentricity = 0.51{{±|0.26|0.22}}
| inclination = 77{{±|5|7}}
| node = <!--Longitude of node (in degrees)-->
| periastron = <!--Periastron epoch-->
| periarg = <!--Argument of periastron (in degrees), secondary -->
| periarg_primary = <!--Argument of periastron (in degrees), primary -->
| k1 = <!-- Velocity semi-amplitude (SB1, or primary in SB2), in km/s -->
| k2 = <!-- Velocity semi-amplitude (secondary in SB2), in km/s -->
}}
{{Starbox detail
| source = <ref name=Cortes-Zuleta2020/>
| component1=BD-07 436A
| component2=BD-07 436B
| mass = 0.903{{±|0.066|0.059}}
| mass2 = 0.71{{±|0.06}}<ref name=Maxted2012/>
| radius = 0.910{{±|0.025|0.023}}
| radius2 = 0.69{{±|0.12}}<ref name=Maxted2012/>
| gravity = 4.476{{±|0.014|0.015}}
| gravity2= 4.6{{±|0.15}}<ref name=Maxted2012/>
| luminosity =  0.743{{±|0.065|0.058}}
| temperature =  5617{{±|72}}
| temperature2 = 5570{{±|240}}<ref name=Evans2017>{{citation|arxiv=1709.07476|title=High-resolution Imaging of Transiting Extrasolar Planetary systems (HITEP). II. Lucky Imaging results from 2015 and 2016|year=2018|doi=10.1051/0004-6361/201731855|last1=Evans|first1=D. F.|last2=Southworth|first2=J.|last3=Smalley|first3=B.|last4=Jørgensen|first4=U. G.|last5=Dominik|first5=M.|last6=Andersen|first6=M. I.|last7=Bozza|first7=V.|last8=Bramich|first8=D. M.|last9=Burgdorf|first9=M. J.|last10=Ciceri|first10=S.|last11=d'Ago|first11=G.|last12=Figuera Jaimes|first12=R.|last13=Gu|first13=S.-H.|last14=Hinse|first14=T. C.|last15=Henning|first15=Th.|last16=Hundertmark|first16=M.|last17=Kains|first17=N.|last18=Kerins|first18=E.|last19=Korhonen|first19=H.|last20=Kokotanekova|first20=R.|last21=Kuffmeier|first21=M.|last22=Longa-Peña|first22=P.|last23=Mancini|first23=L.|last24=MacKenzie|first24=J.|last25=Popovas|first25=A.|last26=Rabus|first26=M.|last27=Rahvar|first27=S.|last28=Sajadian|first28=S.|last29=Snodgrass|first29=C.|last30=Skottfelt|first30=J.|journal=Astronomy & Astrophysics|volume=610|pages=A20|bibcode=2018A&A...610A..20E|s2cid=53400492|display-authors=29}}</ref>
| metal_fe = −0.10{{±|0.10|0.11}}
| metal_fe2 = -0.11{{±|0.19}}<ref name=Maxted2012/>
| rotation = 15.4{{±|0.5}}<ref name=Gallet2020>{{citation|arxiv=2006.07880|title=TATOO: Tidal-chronology standalone tool to estimate the age of massive close-in planetary systems|year=2020|doi=10.1051/0004-6361/202038058|last1=Gallet|first1=F.|author2=Gallet|journal=Astronomy & Astrophysics|volume=641|pages=A38|bibcode=2020A&A...641A..38G|s2cid=219687851}}</ref>
| rotational_velocity = 4.0{{±|0.2}}
| rotational_velocity2 = 2.8{{±|0.5}}<ref name=Maxted2012/>
| age_gyr = 5<ref name=Salz2015/>
| age_gyr2 = >9<ref name=Salz2015/>
}}
{{Starbox catalog
| names = {{odlist|WASP=77|TYC=4697-201-1|TOI=398|2MASS=J02283722-0703384|Gaia DR2=5178405479960844160}}<ref name=simbad/>
}}
{{Starbox reference
| Simbad = BD-07 436
}}
{{Starbox end}}

'''BD-07 436''', also known as '''WASP-77''' since 2012,<ref name=Maxted2012/> is a binary [[Astronomy:Star system|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.<ref name=Salz2015/> The  BD-07 436 system's concentration of heavy elements is similar to the Sun. Its stars display moderate chromospheric activity, including [[Physics:X-ray|x-ray]] [[Astronomy:Solar flare|flares]].<ref name=Salz2015>{{citation|arxiv=1502.00576|title=High-energy irradiation and mass loss rates of hot Jupiters in the solar neighborhood|year=2015|doi=10.1051/0004-6361/201425243|last1=Salz|first1=M.|last2=Schneider|first2=P. C.|last3=Czesla|first3=S.|last4=Schmitt|first4=J. H. M. M.|journal=Astronomy & Astrophysics|volume=576|pages=A42|bibcode=2015A&A...576A..42S|s2cid=55139248}}</ref>

The primary is a [[Astronomy:G-type main-sequence star|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.<ref name=Gallet2020/> The secondary is a [[Astronomy:K-type main-sequence star|K-type main-sequence star]] BD-07 436B orbiting at a distance of 461{{±|200|140}} [[Astronomy:Astronomical unit|AU]].<ref name="Evans2017" />

==Planetary system==
In 2012 a [[Astronomy:Transit|transiting]] [[Astronomy:Hot Jupiter|hot Jupiter]] planet b was detected on a very tight, circular orbit.<ref name=Maxted2012>{{citation|arxiv=1211.6033|title=WASP-77 Ab: A transiting hot Jupiter planet in a wide binary system|year=2012|doi=10.1086/669231|last1=Maxted|first1=P. F. L.|last2=Anderson|first2=D. R.|last3=Collier Cameron|first3=A.|last4=Doyle|first4=A. P.|last5=Fumel|first5=A.|last6=Gillon|first6=M.|last7=Hellier|first7=C.|last8=Jehin|first8=E.|last9=Lendl|first9=M.|last10=Pepe|first10=F.|last11=Pollacco|first11=D. L.|last12=Queloz|first12=D.|last13=Ségransan|first13=D.|last14=Smalley|first14=B.|last15=Southworth|first15=K.|last16=Smith|first16=A. M. S.|last17=Triaud|first17=A. H. M. J.|last18=Udry|first18=S.|last19=West|first19=R. G.|journal=Publications of the Astronomical Society of the Pacific|volume=125|issue=923|pages=48–55|s2cid=53552999}}</ref> The planet may have an extended gaseous envelope and is losing mass.<ref name=Salz2015/> Its equilibrium temperature is 1715{{±|26|25}} [[Kelvin|K]],<ref name=Cortes-Zuleta2020/>the nightside temperature measured in 2019 is 1786{{±|84}} [[Kelvin|K]],<ref>{{citation|arxiv=1901.07040|year=2020|doi=10.3847/1538-3881/ab6cff|last1=Garhart|first1=Emily|last2=Deming|first2=Drake|last3=Mandell|first3=Avi|last4=Knutson|first4=Heather A.|last5=Wallack|first5=Nicole|last6=Burrows|first6=Adam|last7=Fortney|first7=Jonathan J.|last8=Hood|first8=Callie|last9=Seay|first9=Christopher|last10=Sing|first10=David K.|last11=Benneke|first11=Björn|last12=Fraine|first12=Jonathan D.|last13=Kataria|first13=Tiffany|last14=Lewis|first14=Nikole|last15=Madhusudhan|first15=Nikku|last16=McCullough|first16=Peter|last17=Stevenson|first17=Kevin B.|last18=Wakeford|first18=Hannah|title=Statistical Characterization of Hot Jupiter Atmospheres Using Spitzer's Secondary Eclipses|journal=The Astronomical Journal|volume=159|issue=4|page=137|bibcode=2020AJ....159..137G|s2cid=119209434 |doi-access=free }}</ref> and dayside planetary temperature measured in 2020 is 1842{{±|34|33}} [[Kelvin|K]].<ref name=Wong2020>{{citation|arxiv=2003.06407|title=Systematic phase curve study of known transiting systems from year one of the TESS mission|year=2020|doi=10.3847/1538-3881/ababad|last1=Wong|first1=Ian|last2=Shporer|first2=Avi|last3=Daylan|first3=Tansu|last4=Benneke|first4=Björn|last5=Fetherolf|first5=Tara|last6=Kane|first6=Stephen R.|last7=Ricker|first7=George R.|last8=Vanderspek|first8=Roland|last9=Latham|first9=David W.|last10=Winn|first10=Joshua N.|last11=Jenkins|first11=Jon M.|last12=Boyd|first12=Patricia T.|last13=Glidden|first13=Ana|last14=Goeke|first14=Robert F.|last15=Sha|first15=Lizhou|last16=Ting|first16=Eric B.|last17=Yahalomi|first17=Daniel|journal=The Astronomical Journal|volume=160|issue=4|page=155|bibcode=2020AJ....160..155W|s2cid=212717799 |doi-access=free }}</ref>

Water vapour was detected on the planetary dayside of WASP-77Ab, indicating C/O ratio similar to solar or even lower.<ref>{{citation|arxiv=2203.01463|year=2022|title=Confirmation of Water Absorption in the Thermal Emission Spectrum of the Hot Jupiter WASP-77Ab with HST/WFC3|doi=10.3847/1538-3881/ac658f |last1=Mansfield |first1=Megan |last2=Wiser |first2=Lindsey |last3=Stevenson |first3=Kevin B. |last4=Smith |first4=Peter |last5=Line |first5=Michael R. |last6=Bean |first6=Jacob L. |last7=Fortney |first7=Jonathan J. |last8=Parmentier |first8=Vivien |last9=Kempton |first9=Eliza M.-R. |last10=Arcangeli |first10=Jacob |last11=Désert |first11=Jean-Michel |last12=Kilpatrick |first12=Brian |last13=Kreidberg |first13=Laura |last14=Malik |first14=Matej |journal=The Astronomical Journal |volume=163 |issue=6 |page=261 |bibcode=2022AJ....163..261M |s2cid=247223194 |doi-access=free }}</ref>

{{OrbitboxPlanet begin
| name = BD-07 436A
| table_ref =<ref name=Cortes-Zuleta2020>{{citation|arxiv=2001.11112|title=TraMoS V. Updated ephemeris and multi-epoch monitoring of the hot Jupiters WASP-18Ab, WASP-19b, and WASP-77Ab|year=2020|doi=10.1051/0004-6361/201936279|last1=Cortes-Zuleta|first1=Pia|last2=Rojo|first2=Patricio|last3=Wang|first3=Songhu|last4=Hinse|first4=Tobias C.|last5=Hoyer|first5=Sergio|last6=Sanhueza|first6=Bastian|last7=Correa-Amaro|first7=Patricio|last8=Albornoz|first8=Julio|journal=Astronomy & Astrophysics|volume=A98|page=636|bibcode=2020A&A...636A..98C|s2cid=210966021}}</ref>
}}
{{OrbitboxPlanet
| exoplanet = Ab
| mass =  1.667{{±|0.068|0.064}}
| radius =  1.230{{±|0.031|0.029}}
| semimajor =   0.02335{{±|0.00045|0.00043}}
| period =      1.36002854{{±|0.00000062}}
| eccentricity = 0.0074{{±|0.0069|0.0049}}
| inclination =   88.91{{±|0.74|0.95}}
}}
{{Orbitbox end}}

==References==
{{Reflist|refs=
<ref name=simbad>{{cite simbad |title=BD-07 436}}</ref>
}}

{{Sky|02|28|37.226|-|07|03|38.39}}


{{DEFAULTSORT:BD-07 436}}
[[Category:G-type main-sequence stars]]
[[Category:K-type main-sequence stars]]
[[Category:Binary stars]]
[[Category:Planetary systems with one confirmed planet]]
[[Category:Planetary transit variables]]
[[Category:2MASS objects|J02283722-0703384]]
[[Category:Durchmusterung objects]]



{{Sourceattribution|BD-07 436}}