Ross 458

{{Starbox image

| image = 250px

| caption = Image of Ross 458 with the legacy surveys. The companion is the red object marked with an crosshair in the lower right.

}}

{{Starbox observe

| epoch = J2000

| constell = Virgo

| ra = {{RA|13|00|46.557}}

| dec = {{DEC|+12|22|32.68}}

| appmag_v = 9.79

}}

{{Starbox character

| type = Main sequence

| class = {{nowrap|M0.5 + M7.0}}

| b-v = 1.44

| u-b = 1.12

| variable =

}}

{{Starbox astrometry

| radial_v = {{val|-12.33|0.32}}

| prop_mo_ra = {{val|-628.7|0.184}}

| prop_mo_dec = {{val|-33.5|0.133}}

| pm_footnote =

| parallax = 86.9010

| p_error = 0.1170

| parallax_footnote =

| absmag_v = +9.47

}}

{{Starbox orbit

| reference =

| period = 13.63{{±|0.03}}

| axis_unitless = {{val|4.93|0.01|ul=AU}}

| eccentricity = 0.245{{±|0.001}}

| inclination = 130.3{{±|0.3}}

| node = 56.25{{±|0.17}}

| periastron = 2007.67{{±|0.02}}

| periarg = 157.5{{±|0.6}}

}}

{{Starbox detail

| component1 = Primary (A)

| mass = 0.553{{±|0.007}}

| radius = {{val|0.473|0.021|u=Solar radius}}
0.368{{±|0.031}}

| luminosity = {{val|0.044|0.016|0.012}}

| temperature = 3,484{{±|50}}

| gravity =

| metal_fe = 0.09{{±|0.10}}

| age_myr = 400–800

| rotation = {{val|2.89|u=days}}

| rotational_velocity = 9.6{{±|0.9}}

| component2 = Secondary (B)

| mass_mj2 = {{val|88.918|1.836|2.844}}{{cite journal |last1=Feng |first1=Fabo |last2=Butler |first2=R. Paul |display-authors=etal |date=August 2022 |title=3D Selection of 167 Substellar Companions to Nearby Stars |journal=The Astrophysical Journal Supplement Series |volume=262 |issue=21 |page=21 |doi=10.3847/1538-4365/ac7e57 |arxiv=2208.12720 |bibcode=2022ApJS..262...21F |s2cid=251864022 |doi-access=free }}

}}

{{Starbox detail|no_heading=y

|component=C

|mass_mj={{val|11.7|3.6|3}}

|radius_rj={{val|1.1|0.05}}

|luminosity={{val|2.51|e=-6}}

|gravity={{val|4.38|0.16|0.17}}

|temperature={{val|682|16|17}}

}}

{{Starbox catalog

| names = {{odlist | V=DT Vir | BD=+13°2618 | GJ=494 | HIP=63510 | LHS=2665 | LTT=13752 | Ross=458 | Wolf=462 }}

}}

{{Starbox reference

| Simbad = V*+DT+Vir

| ARICNS = 01010

}}

Ross 458, also referred to as DT Virginis, is a binary star system in the constellation of Virgo. It has an apparent visual magnitude of 9.79 and is located at a distance of 37.6 light-years from the Sun. Both of the stars are low-mass red dwarfs with at least one of them being a flare star. This binary system has a circumbinary sub-stellar companion.

Description

File:DTVirLightCurve.png for Ross 458. The main plot, adapted from Shakhovskaya (1969), shows the intensity of a flare relative to the star's quiescent intensity. The inset plot, adapted from Kiraga (2012), shows the periodic variation.]]

This star was mentioned as a suspected variable by M. Petit in 1957. In 1960, O. J. Eggen classified it as a member of the Hyades moving group based on the system's space motion; it is now considered a likely member of the Carina Near Moving Group. Two flares were reported from this star in 1969 by N. I. Shakhovskaya, confirming it as a flare star. It was identified as an astrometric binary in 1994 by W. D. Heintz, who found a period of 14.5 years. The pair were resolved using adaptive optics in 1999. Early mass estimates placed the companion near the substellar limit, and it was initially proposed as a brown dwarf but is now considered late-type red dwarf.

The primary member, component A, is an M-type main-sequence star with a stellar classification of M0.5. It is young, magnetically very active star with a high rate of rotation and strong Hα emission. The star experiences star spots that cover 10–15% of the surface It is smaller and less massive than the Sun. The star is radiating just 4.4% of the luminosity of the Sun from its photosphere at an effective temperature of 3,484 K.

Planetary system

A distant sub-stellar companion to the binary star system was discovered in 2010 as part of a deep infrared sky survey. This is most likely a T8 spectral type brown dwarf with an estimated rotation period of {{val|6.75|1.58|u=hours}}. The object varies slightly in brightness, which may be due to patchy clouds. The companion lacks detectable oxygen in the atmosphere, implying its formation from sequestrated source or peculiar atmospheric chemistry.{{citation|arxiv=2303.16863|year=2023|title=The puzzle of the formation of T8 dwarf Ross 458c|doi=10.1093/mnras/stad753 |last1=Gaarn |first1=Josefine |last2=Burningham |first2=Ben |last3=Faherty |first3=Jacqueline K. |last4=Visscher |first4=Channon |last5=Marley |first5=Mark S. |last6=Gonzales |first6=Eileen C. |last7=Calamari |first7=Emily |last8=Bardalez Gagliuffi |first8=Daniella |last9=Lupu |first9=Roxana |last10=Freedman |first10=Richard |journal=Monthly Notices of the Royal Astronomical Society |volume=521 |issue=4 |pages=5761–5775 |doi-access=free }}

{{OrbitboxPlanet begin

| period_unit = year

| table_ref = {{Cite Exoplanet Archive|Ross 458}}

}}

{{OrbitboxPlanet

| exoplanet = C

| mass = 11.7

| radius = 1.1

| period =

| semimajor = 1,110

| eccentricity =

}}

References

{{Reflist|refs=

{{cite journal |bibcode=2012AstL...38..331A |title=XHIP: An extended hipparcos compilation |last1=Anderson |first1=E. |last2=Francis |first2=Ch. |journal=Astronomy Letters |date=2012 |volume=38 |issue=5 |page=331 |doi=10.1134/S1063773712050015 |arxiv=1108.4971 }}

{{cite journal

| title=Spottedness of the emission-line dwarf stars BF CVn, DT Vir, EQ Vir, and V1396 Cyg from photoelectric and photographic observations

| last1=Alekseev | first1=I. Y. | last2=Bondar | first2=N. I.

| journal=Astronomy Letters

| date=1997 | volume=23 | issue=2 | pages=257–262

| bibcode=1997AstL...23..257A }}

{{cite journal |last1=Kiraga |first1=M. |title=ASAS Photometry of ROSAT Sources. I. Periodic Variable Stars Coincident with Bright Sources from the ROSAT All Sky Survey |journal=Acta Astronomica |date=March 2012 |volume=62 |issue=1 |pages=67–95 |arxiv=1204.3825 |bibcode=2012AcA....62...67K }}

{{cite journal

| title=Observation and modelling of main-sequence star chromospheres - XIV. Rotation of dM1 stars

| last1=Houdebine | first1=E. R.

| journal=Monthly Notices of the Royal Astronomical Society

| volume=407 | issue=3 | pages=1657–1673 | date=September 2010

| doi=10.1111/j.1365-2966.2010.16827.x

| bibcode=2010MNRAS.407.1657H | doi-access= free}}

{{cite journal

| title=SPIRou Input Catalogue: global properties of 440 M dwarfs observed with ESPaDOnS at CFHT

| last1=Fouqué | first1=Pascal | last2=Moutou | first2=Claire

| last3=Malo | first3=Lison | last4=Martioli | first4=Eder

| last5=Lim | first5=Olivia | last6=Rajpurohit | first6=Arvind

| last7=Artigau | first7=Etienne | last8=Delfosse | first8=Xavier

| last9=Donati | first9=Jean-François | last10=Forveille | first10=Thierry

| last11=Morin | first11=Julien | last12=Allard | first12=France

| last13=Delage | first13=Raphaël | last14=Doyon | first14=René

| last15=Hébrard | first15=Elodie | last16=Neves | first16=Vasco

| display-authors=1 | journal=Monthly Notices of the Royal Astronomical Society

| volume=475 | issue=2 | pages=1960–1986 | date=April 2018

| doi=10.1093/mnras/stx3246 | doi-access=free | arxiv=1712.04490

| bibcode=2018MNRAS.475.1960F }}

{{cite journal

| last=Eggen | first=Olin J. | author-link=Olin Eggen

| title=Stellar Groups, VII. The Structure of the Hyades Group

| journal=Monthly Notices of the Royal Astronomical Society

| volume=120 | issue=6 | pages=540–62 | date=1960

| doi=10.1093/mnras/120.6.540 | doi-access=free

| bibcode=1960MNRAS.120..540E }}

{{cite journal

| title=Understanding the physical properties of young M dwarfs: NIR spectroscopic studies

| display-authors=1 | last1=Khata | first1=Dhrimadri

| last2=Mondal | first2=Soumen | last3=Das | first3=Ramkrishna

| last4=Ghosh | first4=Supriyo | last5=Ghosh | first5=Samrat

| journal=Monthly Notices of the Royal Astronomical Society

| volume=493 | issue=3 | pages=4533–4550 | date=April 2020

| doi=10.1093/mnras/staa427 | doi-access=free | arxiv=2002.05762

| bibcode=2020MNRAS.493.4533K }}

{{cite journal

| title=Cycle period, differential rotation and meridional flow for early M dwarf stars

| last1=Küker | first1=M. | last2=Rüdiger | first2=G.

| last3=Olah | first3=K. | last4=Strassmeier | first4=K. G.

| display-authors=1 | journal=Astronomy & Astrophysics

| volume=622 | pages=A40 | year=2019

| doi=10.1051/0004-6361/201833173 | arxiv=1804.02925

| bibcode=2019A&A...622A..40K | s2cid=118842388 }}

{{cite journal

| title=Recovering saturated images for high dynamic kernel-phase analysis. Application to the determination of dynamical masses for the system Gl 494AB

| last1=Laugier | first1=R. | last2=Martinache | first2=F.

| last3=Ceau | first3=A. | last4=Mary | first4=D.

| last5=N'Diaye | first5=M. | last6=Beuzit | first6=J. -L.

| display-authors=1 | journal=Astronomy & Astrophysics

| volume=623 | id=A164 | pages=8 | date=March 2019

| doi=10.1051/0004-6361/201834387 | arxiv=1901.02824

| bibcode=2019A&A...623A.164L | s2cid=119495214 }}

{{cite journal

| title=New neighbours. III. 21 new companions to nearby dwarfs, discovered with adaptive optics

| display-authors=1 | last1=Beuzit | first1=J. -L.

| last2=Ségransan | first2=D. | last3=Forveille | first3=T.

| last4=Udry | first4=S. | last5=Delfosse | first5=X.

| last6=Mayor | first6=M. | last7=Perrier | first7=C.

| last8=Hainaut | first8=M. -C. | last9=Roddier | first9=C.

| last10=Roddier | first10=F. | last11=Martín | first11=E. L.

| journal=Astronomy and Astrophysics

| volume=425 | pages=997–1008 | date=October 2004

| doi=10.1051/0004-6361:20048006 | arxiv=astro-ph/0106277

| bibcode=2004A&A...425..997B | s2cid=15398860 }}

{{cite journal

| title=On the International Cooperation for the Study of Flare Variable Stars

| last=Petit | first=M.

| journal=Soviet Astronomy

| volume=1 | page=783 | date=October 1957

| bibcode=1957SvA.....1..783P }}

{{Cite journal |last1=Zhang |first1=Zhoujian |last2=Liu |first2=Michael C. |last3=Marley |first3=Mark S. |last4=Line |first4=Michael R. |last5=Best |first5=William M. J. |date=2021-07-01 |title=Uniform Forward-Modeling Analysis of Ultracool Dwarfs. I. Methodology and Benchmarking |arxiv=2011.12294 |journal=The Astrophysical Journal |volume=916 |issue=1 |pages=53 |doi=10.3847/1538-4357/abf8b2 |doi-access=free |bibcode=2021ApJ...916...53Z |issn=0004-637X}}

{{cite journal

| title=Flares of BD +13 2618

| last=Shakhovskaya | first=N. I.

| journal=Information Bulletin on Variable Stars

| volume=361 | page=1 | date=July 1969

| bibcode=1969IBVS..361....1S }}

{{cite journal

| title=Cloud Atlas: Rotational Spectral Modulations and Potential Sulfide Clouds in the Planetary-mass, Late T-type Companion Ross 458C

| last1=Manjavacas | first1=Elena | last2=Apai | first2=Dániel

| last3=Lew | first3=Ben W. P. | last4=Zhou | first4=Yifan

| last5=Schneider | first5=Glenn | last6=Burgasser | first6=Adam J.

| last7=Karalidi | first7=Theodora | last8=Miles-Páez | first8=Paulo A.