NY Virginis#Planetary system
{{Short description|Binary star in the constellation Virgo}}
{{Starbox begin
| name = NY Virginis
}}
{{Starbox image
| image = 250px
| caption = A light curve for NY Virginis, adapted from Kilkenny et al. (1998). The deep drops in brightness are caused by eclipses, and the higher frequency low-amplitude oscillation arises from the rapid pulsation of the B-type subdwarf.
}}
{{Starbox observe
| epoch = J2000
| dec = {{DEC|-02|01|49.2073}}
| constell = Virgo
}}
{{Starbox character
| variable = EA + RPHS{{cite journal|bibcode=2009yCat....102025S|title=VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)|journal=VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S|volume=1|pages=B/gcvs|display-authors=etal|last1=Samus|first1=N. N.|last2=Durlevich|first2=O. V.|year=2009}}
}}
{{Starbox astrometry
| prop_mo_ra = {{val|-6.145|0.054}}
| prop_mo_dec = {{val|-12.054|0.025}}
| parallax = 1.6801
| p_error = 0.0376
}}
{{Starbox orbit
| primary = NY Virginis A
| name = NY Virginis B
| period =
| period_unitless = 0.101015968166 d
| axis =
| axis_unitless = 0.0160 AU
| eccentricity = 0.46
| inclination =
| node =
| periastron =
| periarg =
| periarg_primary =
| k1 =
| k2 =
}}
{{Starbox detail
|component1=NY Virginis A
|component2=NY Virginis B
| mass = {{val|0.471|0.006}}
| mass2= 0.13
| radius = {{val|0.1474|0.0009}}
| radius2= 0.155
| gravity = 5.76
| gravity2= 5.16
| luminosity = {{val|23.3|1.5}}
| temperature = {{val|32850|175|fmt=commas}}
| metal_fe =
| rotational_velocity =
| age_gyr =
}}
{{Starbox catalog
| names = {{odlist|GSC=04966-00491|2MASS=J13384814-0201491|Gaia DR2=3637481302758519040}}, PG 1336−018
}}
{{Starbox reference
| Simbad = NY+Vir
}}
{{Starbox end}}
NY Virginis is a binary star about {{val|1940|fmt=commas|u=light-years}} away. The primary belongs to the rare class of subdwarf B stars, being former red giants with their hydrogen envelope completely stripped by a stellar companion. The companion is a red dwarf star. The binary nature of NY Virginis was first identified in 1998,{{cite journal |bibcode=1998MNRAS.296..329K |title=The EC 14026 stars - VIII. PG 1336-018: A pulsating SDB star in an HWVir-type eclipsing binary |last1=Kilkenny |first1=D. |last2=O'Donoghue |first2=D. |last3=Koen |first3=C. |last4=Lynas-Gray |first4=A. E. |last5=Van Wyk |first5=F. |journal=Monthly Notices of the Royal Astronomical Society |year=1998 |volume=296 |issue=2 |page=329 |doi=10.1046/j.1365-8711.1998.01432.x |doi-access=free }} and the extremely short orbital period of {{val|0.101016|ul=d}}, together with brightness variability on the timescale of 200 seconds was noticed, resulting in the identification of the primary star as a B-type subdwarf in 2003.{{cite journal |bibcode=2003MNRAS.345..834K |title=A Whole Earth Telescope campaign on the pulsating subdwarf B binary system PG 1336-018 (NY Vir) |last1=Kilkenny |first1=D. |last2=Reed |first2=M. D. |last3=O'Donoghue |first3=D. |last4=Kawaler |first4=S. D. |last5=Mukadam |first5=A. |last6=Kleinman |first6=S. J. |last7=Nitta |first7=A. |last8=Metcalfe |first8=T. S. |last9=Provencal |first9=J. L. |last10=Watson |first10=T. K. |last11=Sullivan |first11=D. J. |last12=Sullivan |first12=T. |last13=Shobbrook |first13=R. |last14=Jiang |first14=X. J. |last15=Joshi |first15=S. |last16=Ashoka |first16=B. N. |last17=Seetha |first17=S. |last18=Leibowitz |first18=E. |last19=Ibbetson |first19=P. |last20=Mendelson |first20=H. |last21=Meištas |first21=E. |last22=Kalytis |first22=R. |last23=Ališauskas |first23=D. |last24=Martinez |first24=P. |last25=Van Wyk |first25=F. |last26=Stobie |first26=R. S. |last27=Marang |first27=F. |last28=Zola |first28=S. |last29=Krzesinski |first29=J. |last30=Ogłoza |first30=W. |journal=Monthly Notices of the Royal Astronomical Society |year=2003 |volume=345 |issue=3 |page=834 |doi=10.1046/j.1365-8711.2003.07007.x |display-authors=29 |doi-access=free |hdl=10183/89981 |hdl-access=free }} Under a proposed classification scheme for hot subdwarfs it would be class sdB1VII:He1. This non-standard system indicates that it is a "normal" luminosity for a hot subdwarf and that the spectrum is dominated by hydrogen rather than helium.{{cite journal |doi=10.1051/0004-6361/201219433 |title=An MK-like system of spectral classification for hot subdwarfs |year=2013 |last1=Drilling |first1=J. S. |last2=Jeffery |first2=C. S. |last3=Heber |first3=U. |last4=Moehler |first4=S. |last5=Napiwotzki |first5=R. |journal=Astronomy & Astrophysics |volume=551 |pages=A31 |bibcode=2013A&A...551A..31D |doi-access=free }}
Planetary system
In 2011, variations in the timing of the binary star's eclipses were used to infer the presence of a superjovian planet, NY Virginis (AB) b, on a wide orbit, with a second planet being suspected. A study in 2014 found that a two-planet model was preferred. The orbits of these two planets are near or at a 3:10 mutual orbital resonance. Another two-planet model with significant orbital eccentricity, updated to account for changes in eclipse timing not predicted by previous models, was published in 2019.
Studies in 2022 have noted that since planetary models generally fail to predict subsequent changes in eclipse timing, and the most recent two-planet model as of 2021 results in orbits that are unstable on an astronomically-short timescale.
However, in 2023 another model with circular orbits was proposed, which gives stability to the system. The same team also find that it is valid that there are exoplanets in the system creating the eclipe timing variations, and that the moderate eccentricites of the previous model likely caused the orbital instability.
{{OrbitboxPlanet begin
}}
{{OrbitboxPlanet
| exoplanet = b
| mass = {{val|2.164|0.100|0.099|p=>}}
| radius =
| semimajor = {{val|3.540|0.038|0.036|p=>}}
| period = {{val|3140|50|48}}
| eccentricity = 0
| inclination =
}}
{{OrbitboxPlanet
| exoplanet = c
| mass = {{val|3.939|0.159|0.113|p=>}}
| radius =
| semimajor = {{val|6.52|0.22|0.18|p=>}}
| period = {{val|8309|398|326}}
| eccentricity = 0
| inclination =
}}
{{Orbitbox end}}
References
{{reflist|refs=
{{cite simbad|title=V* NY Vir|access-date = 18 September 2020}}
{{Cite Gaia DR3|3637481302758519040}}
{{cite journal |last1=Er |first1=Huseyin |last2=Özdönmez |first2=Aykut |last3=Nasiroglu |first3=Ilham |date=October 2021 |title=New observations of the eclipsing binary system NY Vir and its candidate circumbinary planets |journal=Monthly Notices of the Royal Astronomical Society |volume=507 |issue=1 |pages=809–817 |doi=10.1093/mnras/stab2054 |doi-access=free |arxiv=2107.07003 |bibcode=2021MNRAS.507..809E}}
{{cite journal |last1=Pulley |first1=D. |last2=Sharp |first2=I. D. |last3=Mallett |first3=J. |last4=von Harrach |first4=S. |date=August 2022 |title=Eclipse timing variations in post-common envelope binaries: Are they a reliable indicator of circumbinary companions? |journal=Monthly Notices of the Royal Astronomical Society |volume=514 |issue=4 |pages=5725–5738 |doi=10.1093/mnras/stac1676 |doi-access=free |arxiv=2206.06919 |bibcode=2022MNRAS.514.5725P}}
}}
{{Sky|13|38|48.1466|-|02|01|49.2095}}
{{Virgo (constellation)}}
{{DEFAULTSORT:NY Virginis}}
Category:Virgo (constellation)
Category:Planetary systems with two confirmed planets
Category:Multi-star planetary systems
Category:Very rapidly pulsating hot stars