View source for Wolf 424

{{Short description|Star in constellation of Virgo}}
{{Sky|12|33|17.38|+|09|01|15.8|14.59}}
{{Starbox begin}}
{{Starbox image
|image={{Location map|100x100|AlternativeMap=Virgo_constellation_map.svg
|alt=Wolf 424 is located in the constellation Virgo.
|caption=Location of Wolf 424 in the constellation [[Virgo (constellation)|Virgo]]|border=infobox|mark=Red_pog.png|width=300
|label=<br/>Wolf 424
|position=left
|lat=67.3
|long=64.6
}}|caption=
}}
{{Starbox observe
| constell=[[Virgo (constellation)|Virgo]]<ref name=constellation/>
| epoch=J2000
| ra={{RA|12|33|17.38}}<ref name=vizier_2_246/>
| dec={{DEC|+09|01|15.8}}<ref name=vizier_2_246/>
| appmag_v={{nowrap|A: 13.22 ± 0.01}}<br/>{{nowrap|B: 13.21 ± 0.01}}<ref name=aj117_1_562/>
}}
{{Starbox character
| class=dM6e/dM6e<ref name=mnras368_3_1392/>
| b-v=
| u-b=
| variable=[[Flare star]]s<ref name=mnras368_3_1392/>
}}
{{Starbox astrometry
| radial_v = −2<ref name=gcsrv/>
| parallax = 227.041
| p_error = 0.389
| parallax_footnote = <ref name="Chevalier2023"/>
}}
{{Starbox astrometry|no_heading=y
| component1 = Wolf 424 A
| prop_mo_ra={{val|-1795.661|fmt=commas}}
| prop_mo_dec={{val|217.789}}
| pm_footnote=<ref name=GaiaDR3a/>
| absmag_v=15.03<ref name=RECONS/>
| component2 = Wolf 424 B
| prop_mo_ra2={{val|-1710.468|fmt=commas}}
| prop_mo_dec2={{val|203.098}}
| pm_footnote2=<ref name=GaiaDR3b/>
| absmag_v2=15.02<ref name=RECONS/>
}}
{{Starbox visbin
| reference=<ref name=Benedict2016/>
| primary=Wolf 424 A
| name=Wolf 424 B
| period={{val|{{convert|5772.3|day|year|disp=number}}|{{convert|9.4|day|year|disp=number}}}}
| axis_unitless={{val|0.9167|0.0017|ul="}}<ref name=Benedict2016/><br>({{val|4.062|0.098|ul=AU}})<ref name=aj117_1_562/>
| eccentricity={{val|0.301|0.002}}
| inclination={{val|103.3|0.7}}
| node={{val|143.5|0.1}}
| periarg={{val|350.7|0.5}}
| periastron={{val|1992.297|0.056|fmt=none}}<ref name=aj117_1_562/>
}}
{{Starbox detail
| component1= A
| mass= {{val|0.1379|0.0023}}<ref name="Chevalier2023"/>
| radius = {{val|0.150|0.019}}<ref name=CARMENES-IX/>
| temperature = {{Val|2966|7|fmt=commas}}<ref name=Houdebine2019/>
| component2 = B
| mass2 = {{val|0.1258|0.0022}}<ref name="Chevalier2023"/>
| radius2 = {{val|0.153|0.019}}<ref name=CARMENES-IX/>
| temperature2 = {{Val|2966|7|fmt=commas}}<ref name=Houdebine2019/>
}}
{{Starbox catalog
| names= {{odlist | V=FL Vir | Ci 20=716 | G=12-43 | G2=60-14 | GCRV=7553 | GJ=473 | GSC=00874-00306 | LFT=923 | LHS=333 | LTT=13546 | PLX=2890 | Wolf=424}}, Cl* Melotte 25 EGG 43, [[USNO]]-B1.0 0990-00217846, [[Van Vleck Observatory|VVO]] 74, [[Einstein Observatory|2E]] 2769, [[JP11]] 5148, [[JP11]] 5149<ref name=SIMBAD/>
}}
{{Starbox reference
| Simbad=Wolf+424|sn=The system
| Simbad2=Wolf+424+A|sn2=A
| Simbad3=Wolf+424+B|sn3=B
| ARICNS=00975|an=A
| ARICNS2=00976|an2=B
}}
{{Starbox end}}

'''Wolf 424''' is a [[binary star]] system comprising two [[red dwarf]] stars. The stars are located at a distance of 14.37 [[light-year]]s and hence are among the [[List of nearest stars|nearest stars]], but due to their faint intrinsic brightness, they are not visible to the [[naked eye]]. Wolf 424 is located in the constellation [[Virgo (constellation)|Virgo]], between the stars [[Epsilon Virginis|ε Virginis]] and [[Omicron Virginis|ο Virginis]].

==Description==
[[Image:FLVirLightCurve.png|thumb|left|An [[Photometric_system#Photometric_letters|ultraviolet band]] [[light curve]] for FL Virginis, adapted from Moffett (1972).<ref name="Moffett"/> The plot shows intensity above the star's quiescent intensity.]]
The close binary nature of this star was discovered by Dutch American astronomer [[Dirk Reuyl]] in 1941, based upon an elongation of the star found in photographs.<ref name=aj117_1_562/> The two stars in the Wolf 424 system orbit about each other with a [[semi-major axis]] of 4.1 [[Astronomical Units|AU]] and an [[eccentricity (orbit)|eccentricity]] of 0.3. The stars have an [[orbital period]] of 15.5 years and have a combined apparent magnitude of about 12.5.

Wolf 424A and Wolf 424B are similar-[[stellar spectrum|spectrum]] and similar-size stars, both [[red dwarf]]s  with masses of {{solar mass|link=y|0.138 and 0.126}} and radii of {{solar radius|0.150 and 0.153}}, respectively.<ref name=CARMENES-IX/> In 1967, it was discovered that both are [[flare star]]s that undergo random increases in luminosity. The system has been [[Variable star designation|designated]] FL Virginis, and may experience sunspot activity. The stars may undergo variation in the level of flare activity over periods lasting several years.<ref name=mnras368_3_1392/>
{{clear left}}

==References==
{{reflist|refs=

<ref name=SIMBAD>{{cite simbad|title=V* FL Vir}}</ref>

<ref name=GaiaDR3a>{{Cite Gaia DR3|3902874650602495232}}</ref>
<ref name=GaiaDR3b>{{Cite Gaia DR3|3902874650601954816}}</ref>

<ref name=constellation>{{cite constellation|Wolf 424}}</ref>

<ref name="Moffett">{{cite journal |last1=Moffett |first1=T. J. |title=Wolf 424: a neglected flare star |journal=Monthly Notices of the Royal Astronomical Society |date=January 1973 |volume=164 |pages=11–20 |doi=10.1093/mnras/164.1.11 |bibcode=1973MNRAS.164...11M |doi-access=free }}</ref>

<ref name=vizier_2_246>{{cite journal |bibcode=2003yCat.2246....0C |title=VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) |journal=CDS/ADC Collection of Electronic Catalogues |pages=II/246 |volume=2246 |last1=Cutri |first1=Roc M. |last2=Skrutskie |first2=Michael F. |last3=Van Dyk |first3=Schuyler D. |last4=Beichman |first4=Charles A. |last5=Carpenter |first5=John M. |last6=Chester |first6=Thomas |last7=Cambresy |first7=Laurent |last8=Evans |first8=Tracey E. |last9=Fowler |first9=John W. |last10=Gizis |first10=John E. |last11=Howard |first11=Elizabeth V. |last12=Huchra |first12=John P. |last13=Jarrett |first13=Thomas H. |last14=Kopan |first14=Eugene L. |last15=Kirkpatrick |first15=J. Davy |last16=Light |first16=Robert M. |last17=Marsh |first17=Kenneth A. |last18=McCallon |first18=Howard L. |last19=Schneider |first19=Stephen E. |last20=Stiening |first20=Rae |last21=Sykes |first21=Matthew J. |last22=Weinberg |first22=Martin D. |last23=Wheaton |first23=William A. |last24=Wheelock |first24=Sherry L. |last25=Zacarias |first25=N. |year=2003 |url=http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=II/246 |s2cid=115529446}}</ref>

<ref name=Benedict2016>{{cite journal|bibcode=2016AJ....152..141B|doi=10.3847/0004-6256/152/5/141|arxiv=1608.04775|title=The Solar Neighborhood. XXXVII. The Mass–Luminosity Relation for Main-Sequence M Dwarfs|journal=The Astronomical Journal|volume=152|issue=5|pages=141|year=2016|last1=Benedict|first1=G. F.|last2=Henry|first2=T. J.|last3=Franz|first3=O. G.|last4=McArthur|first4=B. E.|last5=Wasserman|first5=L. H.|last6=Jao|first6=Wei-Chun|last7=Cargile|first7=P. A.|last8=Dieterich|first8=S. B.|last9=Bradley|first9=A. J.|last10=Nelan|first10=E. P.|last11=Whipple|first11=A. L.|s2cid=54029447 |doi-access=free }}</ref>

<ref name=Houdebine2019>{{cite journal |doi=10.3847/1538-3881/ab23fe |title=The Mass–Activity Relationships in M and K Dwarfs. I. Stellar Parameters of Our Sample of M and K Dwarfs |journal=The Astronomical Journal |volume=158 |issue=2 |pages=56 |year=2019 |last1=Houdebine |first1=Éric R. |last2=Mullan |first2=D. J. |last3=Doyle |first3=J. G. |last4=de la Vieuville |first4=Geoffroy |last5=Butler |first5=C. J. |last6=Paletou |first6=F. |arxiv=1905.07921 |bibcode=2019AJ....158...56H |s2cid=159041104 |doi-access=free }}</ref>

<ref name=CARMENES-IX>{{Cite journal |last1=Cifuentes |first1=C. |last2=Caballero |first2=J. A. |last3=González-Payo |first3=J. |last4=Amado |first4=P. J. |last5=Béjar |first5=V. J. S. |last6=Burgasser |first6=A. J. |last7=Cortés-Contreras |first7=M. |last8=Lodieu |first8=N. |last9=Montes |first9=D. |last10=Quirrenbach |first10=A. |last11=Reiners |first11=A. |last12=Ribas |first12=I. |last13=Sanz-Forcada |first13=J. |last14=Seifert |first14=W. |last15=Zapatero Osorio |first15=M. R. |date=January 2025 |title=CARMENES input catalogue of M dwarfs. IX. Multiplicity from close spectroscopic binaries to ultra-wide systems |journal=Astronomy and Astrophysics |volume=693 |pages=A228 |doi=10.1051/0004-6361/202452527 |bibcode=2025A&A...693A.228C |issn=0004-6361 }}</ref>

<ref name=gcsrv>{{cite journal | last=Wilson | first=Ralph Elmer | date=1953 | title=General Catalogue of Stellar Radial Velocities | journal=Carnegie Institute Washington D.C. Publication | publisher=Carnegie Institution of Washington | location=Washington | bibcode=1953GCRV..C......0W }}</ref>

<ref name=aj117_1_562>{{cite journal | author=Torres, Guillermo |display-authors=etal  | title=The Nearby Low-Mass Visual Binary Wolf 424 | journal=The Astronomical Journal | volume=117 | issue=1 | pages=562–573 |date=January 1999 | doi=10.1086/300708 | bibcode=1999AJ....117..562T | doi-access=free }}</ref>

<ref name=mnras368_3_1392>{{cite journal | title=Flare variability in the close binary FL Vir | last=Pettersen | first=B. R. |date=May 2006 | journal=[[Monthly Notices of the Royal Astronomical Society]] | volume=368 | issue=3 | pages=1392–1394 | doi=10.1111/j.1365-2966.2006.10210.x | bibcode=2006MNRAS.368.1392P | doi-access=free }}</ref>

<ref name=RECONS>{{cite web | author=Staff | date=January 1, 2010 | url=http://www.recons.org/TOP100.posted.htm | title=List of the Nearest 100 Stellar Systems  | publisher=[[Research Consortium on Nearby Stars]] | access-date=2011-07-01 }}</ref>

<ref name="Chevalier2023">{{cite journal |last1=Chevalier |first1=S. |last2=Babusiaux |first2=C. |display-authors=etal |date=October 2023 |title=Binary masses and luminosities with Gaia DR3 |journal=[[Astronomy & Astrophysics]] |volume=678 |issue= |pages=A19 |doi=10.1051/0004-6361/202347111 |arxiv=2307.16719 |bibcode=2023A&A...678A..19C}}</ref>

}}

==Further reading==
* W. D. Heintz, "Astrometric study of 4 binary stars", 1972, ''Astronomical Journal'', 77, 160.
*{{cite book | last = Cohen | first = E. Richard |author2=David R. Lide |author3=George L. Trigg  | title = AIP Physics Desk Reference | publisher = [[Birkhäuser]] | date = 2003 | pages = 100 | url = https://books.google.com/books?id=JStYf6WlXpgC&pg=PA100 | isbn = 0-387-98973-0}}

==External links==
* [https://archive.today/20010611082957/http://nemesis.stsci.edu/~kochte/wolf-page.html Wolf 424 Data page]
* [http://www.solstation.com/stars/wolf424.htm Wolf 424 AB]
* [http://www.solstation.com/stars/wolf424.jpg A NASA image of Wolf 424 AB]

{{nearest systems|2}}
{{Virgo}}

{{DEFAULTSORT:Wolf 424}}
[[Category:Binary stars]]
[[Category:Local Bubble]]
[[Category:M-type main-sequence stars]]
[[Category:Flare stars]]
[[Category:Virgo (constellation)]]
[[Category:Wolf objects|0424]]
[[Category:Gliese and GJ objects|0473]]
[[Category:Objects with variable star designations|Virginis, FL]]