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TW Piscis Austrini: Difference between revisions

Coordinates: Sky map 22h 56m 24.0533s, −31° 33′ 56.0351″
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{{Short description|Star in the constellation Piscis Austrinus}}
{{Redirect|Fomalhaut B|the extrasolar planet candidate|Fomalhaut b}}
{{Redirect|Fomalhaut B|the former exoplanet candidate|Fomalhaut b}}
{{Starbox begin
{{Starbox begin
| name=TW Piscis Austrini }}
| name=TW Piscis Austrini
}}
{{Starbox image
| image=
{{Location mark
|image=Piscis Austrinus constellation map.svg|alt=|float=center|width=280
|label=|position=right
|mark=Red circle.svg|mark_width=10|mark_link=TW Piscis Austrini
|x=178|y=436
}}
|caption=Location of TW Piscis Austrini (circled)
}}
{{Starbox observe
{{Starbox observe
| epoch=J2000
| epoch = J2000
| constell=[[Piscis Austrinus]]
| ra={{RA|22|56|24.05327}}<ref name=aaa474_2_653/>
| dec={{DEC|−31|33|56.0351}}<ref name=aaa474_2_653/>
| ra = {{RA|22|56|24.05256}}<ref name="GaiaDR3"/>
| appmag_v=6.48<ref name="SIMBAD">{{cite web
| dec = {{DEC|−31|33|56.0306}}<ref name="GaiaDR3"/>
| appmag_v = 5.44–6.51<ref name=gcvs/>
| title=V* TW PsA -- Variable of BY Dra type | work=SIMBAD
}}
| publisher=Centre de Données astronomiques de Strasbourg
| url=http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=GJ+879&submit=SIMBAD+search
| accessdate=2010-01-20 }}</ref>
| constell=[[Piscis Austrinus]] }}
{{Starbox character
{{Starbox character
| class=K5Vp<ref name=aaa505_1_205/>
| class=K5Vp<ref name=aaa505_1_205/>
| b-v=1.10<ref name="clpl4">{{cite journal
| b-v=1.10<ref name=clpl4/>
| u-b=1.02<ref name=clpl4/>
| author=Johnson, H. L.; Iriarte, B.; Mitchell, R. I.; Wisniewskj, W. Z.
| variable=[[BY Draconis variable|BY Draconis]]<ref name=gcvs/>
| title=UBVRIJKL photometry of the bright stars
}}
| journal=Communications of the Lunar and Planetary Laboratory | volume=4 | issue=99 | year=1966
| bibcode=1966CoLPL...4...99J }}</ref>
| u-b=1.02<ref name="clpl4" />
| variable=[[BY Draconis variable|BY Draconis]] }}
{{Starbox astrometry
{{Starbox astrometry
| radial_v=+6<ref name="SIMBAD" />
| radial_v = {{val|+6.79|0.12}}<ref name="GaiaDR3"/>
| prop_mo_ra=−331.11<ref name=aaa474_2_653/>
| prop_mo_ra = {{val|330.203}}
| prop_mo_dec=−158.98<ref name=aaa474_2_653/>
| prop_mo_dec = {{val|−158.602}}
| pm_footnote = <ref name="GaiaDR3"/>
| parallax=131.42
| parallax = 131.5525
| p_error=0.62
| p_error = 0.0275
| parallax_footnote=<ref name=aaa474_2_653/>
| absmag_v=7.08<ref name="age_mam"/> }}
| parallax_footnote = <ref name="GaiaDR3"/>
| absmag_v = 7.08<ref name="age_mam"/>
}}
{{Starbox detail
{{Starbox detail
| mass={{nowrap|0.725 ± 0.036}}<ref name=aaa505_1_205/>
| source=<ref name=Gomes2021/>
| radius={{nowrap|0.629 ± 0.051}}<ref name=aaa505_1_205 />
| mass={{val|0.704|0.016}}
| radius={{val|0.658|0.009}}
| luminosity=0.19<ref name="age_mam"/>
| luminosity=0.19<ref name="age_mam"/>
| temperature={{nowrap|4,711 ± 134}}<ref name=aaa505_1_205/>
| temperature={{val|4610|67|fmt=commas}}
| metal_fe={{val|-0.07|0.03}}
| metal=
| rotation=
| rotation=10.3<ref name=Mamajek/> days
| rotational_velocity=2.93<ref name=aaa505_1_205/>
| rotational_velocity=2.93<ref name=aaa505_1_205/>
| age=4.4 × 10<sup>8</sup><ref name="age_mam"/> }}
| age_myr=440<ref name="age_mam"/>
}}
{{Starbox catalog
{{Starbox catalog
| names=TW PsA, [[Henry L. Giclas catalogue|Gl]] 879, [[Harvard Revised catalogue|HR]] 8721, [[Cordoba Durchmusterung|CD]] -32°17321, [[Henry Draper catalogue|HD]] 216803, [[Luyten Two-Tenths catalogue|LTT]] 9283, [[General Catalogue of Trigonometric Parallaxes|GCTP]] 5562.00, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]] 214197, CP(D)-32 6550, [[Hipparcos catalogue|HIP]] 113283. }}
| names=TW PsA, [[Gliese Catalogue of Nearby Stars|Gl]] 879, [[Harvard Revised catalogue|HR]] 8721, [[Cordoba Durchmusterung|CD]]−32°17321, [[Henry Draper catalogue|HD]] 216803, [[Luyten Two-Tenths catalogue|LTT]] 9283, [[General Catalogue of Trigonometric Parallaxes|GCTP]] 5562.00, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]] 214197, CP(D)−32°6550, [[Hipparcos catalogue|HIP]] 113283<ref name=SIMBAD/>
}}
{{Starbox reference
{{Starbox reference
| Simbad = HD+216803
| Simbad = HD+216803
Line 47: Line 58:
}}
}}
{{Starbox end}}
{{Starbox end}}
'''TW Piscis Austrini''' (also Fomalhaut B) is a dwarf [[star]] in the [[constellation]] [[Piscis Austrinus]]. It lies relatively close to the [[Sun]], at an estimated distance of 24.9 [[light year]]s.
'''TW Piscis Austrini''' (also known as Fomalhaut B) is a [[main sequence]] star in the [[constellation]] [[Piscis Austrinus]]. It lies relatively close to the [[Sun]], at an estimated distance of {{convert|24.8|ly|pc|lk=on|abbr=off}}.
To an observer on Earth the star is visually separated from its larger companion [[Fomalhaut]] (A) by 2 degrees—the width of four [[full moon]]s.<ref name=skyandtelescope2014-10-01/>


[[File:TWPsALightCurve.png|thumb|left| A [[Photometric_system#Photometric_letters|visual band]] [[light curve]] for TW Piscis Austrini, adapted from Busko and Torres (1978).<ref name="Busko"/> The error bar shown on the left-most point applies to all points.]]
The TW in the name is astronomical nomenclature for a [[variable star]]. This is a [[flare star]] of the type known as a [[BY Draconis variable]]. It varies slightly in [[apparent magnitude]], ranging from 6.44 to 6.49 over a 10.3 day period. While smaller than the [[Sun]], it is relatively large for a flare star. Most flare stars are red [[stellar classification|M-type]] dwarfs.
The name TW Piscis Austrini is a [[variable star designation]]. This is a [[variable star]] of the type known as a [[BY Draconis variable]], with surface brightness variations causing the changes as the star rotates. It varies slightly in [[apparent magnitude]], ranging from 6.44 to 6.51 over a 10.3-day period.<ref name=gcvs/>


TW Piscis Austrini lies within a light-year of Fomalhaut.<ref name=schaaf2008/> Due to sharing the same [[proper motion]], and the same estimated age of approximately 440 ± 40 million years, astronomers now consider them to be elements of a multiple [[star system]].<ref name="age_mam"/> A third star, dimmer and more widely separated, [[Fomalhaut C]], gives the system the widest visual separation, to observers from Earth, at approximately 6 degrees.<ref name=skyandtelescope2014-10-01/>
TW Piscis Austrini lies within a [[light year]] of the much brighter star [[Fomalhaut]],<ref>p. 237, ''The Brightest Stars: Discovering The Universe Through The Sky's Most Brilliant Stars'', Fred Schaaf, Hoboken, NJ: John Wiley & Sons, Inc., 2008, ISBN 978-0-471-70410-2.</ref> and the two may be travelling companions that share a common motion through space.
==Planetary system==
In 2019, an [[exoplanet]] candidate around Fomalhaut B was detected by [[astrometry]], but this remains unconfirmed.<ref name=space2019-09-23/><ref name=AstronomicalJournal2019-10-07/>


{{OrbitboxPlanet begin
A 2012 study<ref name="age_mam"/> showed that TW PsA and [[Fomalhaut]] are approximately only 0.28 parsecs (57,000 AU) apart, and share a space velocity within 0.1±0.5&nbsp;km/s, consistent with constituting a physical binary system. Independent age estimates for [[Fomalhaut]] and TW PsA yield similar results, and the age for the system is 440±40 million years.<ref name="age_mam"/>
| name = Fomalhaut B

In 2019 NASA's [[Transiting Exoplanet Survey Satellite]] space telescope found a exoplanet candidate around Fomalhaut B.<ref name=space2019-09-23/><ref name=AstronomicalJournal2019-10-07/>
| table_ref = <ref name=AstronomicalJournal2019-10-07/>
| period_unit = year
}}
{{OrbitboxPlanet hypothetical
| exoplanet = b
| period = {{val|25|52|21}}
| mass = {{val|1.2|0.7|0.6}}
}}
{{Orbitbox end}}


== References ==
==References==
{{reflist|refs=
{{reflist|refs=


<ref name="GaiaDR3">{{Cite Gaia DR3|6604147121141267712}}</ref>
<ref name=age_mam>{{Cite journal | last1=Mamajek | first1=E.E. | title=On the Age and Binarity of Fomalhaut | journal=Astrophysical Journal Letters | volume=754 | issue=2 |date=August 2012 | pages=L20 | doi=10.1088/2041-8205/754/2/L20 | bibcode=2012ApJL..754...20M | arxiv=1206.6353}}</ref>


<ref name=aaa474_2_653>{{citation | last1=van Leeuwen | first1=F. | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 |date=November 2007 | pages=653–664 | doi=10.1051/0004-6361:20078357 | bibcode=2007A&A...474..653V | arxiv=0708.1752 }}</ref>
<ref name="Busko">{{cite journal |last1=Busko |first1=I. C. |last2=Torres |first2=C. A. O. |title=Flare activity by BY Draconis stars |journal=Astronomy and Astrophysics |date=March 1978 |volume=64 |pages=153–160 |bibcode=1978A&A....64..153B |url=https://ui.adsabs.harvard.edu/abs/1978A&A....64..153B |access-date=23 February 2022}}</ref>


<ref name=schaaf2008>{{cite book|author=Fred Schaaf|title=The Brightest Stars: Discovering the Universe through the Sky's Most Brilliant Stars|url=https://books.google.com/books?id=9LT1q0Il3-YC|date=31 March 2008|publisher=Wiley|isbn=978-0-470-24917-8}}</ref>
<ref name=aaa505_1_205>{{citation | display-authors=1 | last1=Demory | first1=B.-O. | last2=Ségransan | first2=D. | last3=Forveille | first3=T. | last4=Queloz | first4=D. | last5=Beuzit | first5=J.-L. | last6=Delfosse | first6=X. | last7=di Folco | first7=E. | last8=Kervella | first8=P. | last9=Le Bouquin | first9=J.-B. |date=October 2009 | title=Mass-radius relation of low and very low-mass stars revisited with the VLTI | journal=Astronomy and Astrophysics | volume=505 | issue=1 | pages=205–215 | doi=10.1051/0004-6361/200911976 | bibcode=2009A&A...505..205D |arxiv = 0906.0602 }}</ref>

<ref name=age_mam>{{Cite journal | last1=Mamajek | first1=E.E. | title=On the Age and Binarity of Fomalhaut | journal=Astrophysical Journal Letters | volume=754 | issue=2 |date=August 2012 | pages=L20 | doi=10.1088/2041-8205/754/2/L20 | arxiv=1206.6353| bibcode=2012ApJ...754L..20M | s2cid=119191190 }}</ref>

<ref name=aaa505_1_205>{{cite journal
| title=Mass-radius relation of low and very low-mass stars revisited with the VLTI
| journal=Astronomy and Astrophysics | volume=505 | issue=1
| date=October 2009 | pages=205–215
| doi=10.1051/0004-6361/200911976
| bibcode=2009A&A...505..205D |arxiv = 0906.0602
|last1=Demory |first1=Brice-Olivier
|last2=Ségransan |first2=Damien
|last3=Forveille |first3=Thierry
|last4=Queloz |first4=Didier
|last5=Beuzit |first5=Jean-Luc
|last6=Delfosse |first6=Xavier
|last7=Di Folco |first7=Emmanuel
|last8=Kervella |first8=Pierre
|last9=Le Bouquin |first9=Jean-Baptiste
|last10=Perrier |first10=Christian
|last11=Benisty |first11=Myriam
|last12=Duvert |first12=Gilles
|last13=Hofmann |first13=Karl-Heinz
|last14=Lopez |first14=Bruno
|last15=Petrov |first15=Romain
|s2cid=14786643
}}</ref>


<ref name=space2019-09-23>
<ref name=space2019-09-23>
Line 70: Line 120:
| url = https://www.space.com/fomalhaut-autumn-star-skywatching.html
| url = https://www.space.com/fomalhaut-autumn-star-skywatching.html
| title = Fomalhaut, 'Royal' Star of Autumn, Swims with the Southern Fish
| title = Fomalhaut, 'Royal' Star of Autumn, Swims with the Southern Fish
| work = [[Space magazine]]
| work = [[Space.com]]
| author = Joe Rao
| author = Joe Rao
| date = 2019-09-23
| date = 2019-09-23
Line 76: Line 126:
| archivedate =
| archivedate =
| accessdate = 2020-06-13
| accessdate = 2020-06-13
| url-status = live
| quote = Believe it or not, an extrasolar planet might also be circling TW Piscis Austrini. NASA's Transiting Exoplanet Survey Satellite (TESS), a space telescope that's searching for planets around the brightest stars in Earth's night sky, recently found a possible candidate circling this star. It's almost the same size as our Earth, and orbits the star about every 10 days at a distance of 7.5 million miles from it.
| quote = Believe it or not, an extrasolar planet might also be circling TW Piscis Austrini. NASA's Transiting Exoplanet Survey Satellite (TESS), a space telescope that's searching for planets around the brightest stars in Earth's night sky, recently found a possible candidate circling this star. It's almost the same size as our Earth, and orbits the star about every 10 days at a distance of 7.5 million miles from it.
}}
}}
Line 103: Line 152:
| first8 = Bruce
| first8 = Bruce
| date = 7 October 2019
| date = 7 October 2019
|volume = 158
| eprint = 1910.02965
|issue = 6
<!-- | class = astro-ph.EP -->
|page = 225
| arxiv = 1910.02965
| doi = 10.3847/1538-3881/ab4c9b
|bibcode = 2019AJ....158..225D
|s2cid = 203902656
|doi-access = free
}}
}}
</ref>
</ref>

<ref name=skyandtelescope2014-10-01>
{{cite news
| url = https://skyandtelescope.org/astronomy-news/fomalhaut-falls-amazing-triple-star10012014/
| title = Fomalhaut: A crazy-wide triple stat
| work = [[Sky & Telescope]]
| author = Bob King
| date = 2014-10-01
| archiveurl =
| archivedate =
| accessdate = 2020-06-13
| quote = Though it may appear isolated in the barren October sky, Fomalhaut has company. It feels the gravitational tug of the magnitude +6.5 star TW Piscis Austrini, 2° to the south. Both are 25 light-years distant and move in tandem across space, partaking of the same proper motion. They form a true double star with an actual separation of 5.5 trillion miles, or 0.91 light-year.
}}
}}
</ref>


<ref name=SIMBAD>{{cite web
== External links ==
| title=V* TW PsA -- Variable of BY Dra type | work=SIMBAD
| publisher=Centre de Données astronomiques de Strasbourg
| url=http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=GJ+879&submit=SIMBAD+search
| accessdate=2010-01-20 }}</ref>

<ref name=clpl4>{{cite journal
| title=UBVRIJKL photometry of the bright stars
| journal=Communications of the Lunar and Planetary Laboratory | volume=4 | issue=99 | year=1966
| page=99
| bibcode=1966CoLPL...4...99J | last1=Johnson | first1=H. L. | last2=Mitchell | first2=R. I. | last3=Iriarte | first3=B. | last4=Wisniewski | first4=W. Z. }}</ref>

<ref name=gcvs>{{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}}</ref>

<ref name=Mamajek>{{cite journal
| author1=Mamajek, Eric E. | display-authors=etal
| title=The Solar Neighborhood. XXX. Fomalhaut C
| journal=The Astronomical Journal
| volume=146 | issue=6 | pages=154–163 | date=2013
| bibcode=2013AJ....146..154M
| doi=10.1088/0004-6256/146/6/154
| arxiv=1310.0764|s2cid=67821813}}</ref>


<ref name=Gomes2021>{{Cite journal |last=Gomes da Silva |first=J. |last2=Santos |first2=N. C. |last3=Adibekyan |first3=V. |last4=Sousa |first4=S. G. |last5=Campante |first5=T. L. |last6=Figueira |first6=P. |last7=Bossini |first7=D. |last8=Delgado-Mena |first8=E. |last9=Monteiro |first9=M. J. P. F. G. |last10=de Laverny |first10=P. |last11=Recio-Blanco |first11=A. |last12=Lovis |first12=C. |date=2021-02-01 |title=Stellar chromospheric activity of 1674 FGK stars from the AMBRE-HARPS sample. I. A catalogue of homogeneous chromospheric activity |url=https://ui.adsabs.harvard.edu/abs/2021A&A...646A..77G |journal=Astronomy and Astrophysics |volume=646 |pages=A77 |doi=10.1051/0004-6361/202039765 |issn=0004-6361|arxiv=2012.10199 }} [https://vizier.cds.unistra.fr/viz-bin/VizieR?-source=J/A%2BA/646/A77&Star=TW%20PsA Fomalhaut B's database entry] at [[VizieR]].</ref>

}}

==External links==
* [http://www.solstation.com/stars/tw-psa.htm TW Piscis Austrini] at SolStation.
* [http://www.solstation.com/stars/tw-psa.htm TW Piscis Austrini] at SolStation.
{{Sky|22|56|24.0533|-|31|33|56.0351|24.8}}
{{Nearest star systems|6}}
{{Nearest star systems|6}}
{{Stars of Piscis Austrinus}}
{{Stars of Piscis Austrinus}}
{{Fomalhaut}}

{{DEFAULTSORT:TW Piscis Austrini}}
[[Category:Piscis Austrinus]]
[[Category:Piscis Austrinus]]
[[Category:K-type main-sequence stars]]
[[Category:K-type main-sequence stars]]
[[Category:BY Draconis variables]]
[[Category:BY Draconis variables]]
[[Category:Objects within 100 ly of Earth]]
[[Category:Objects with variable star designations|Piscis Austrini, TW]]
[[Category:Objects named with variable star designations|Piscis Austrini, TW]]
[[Category:Henry Draper Catalogue objects|216803]]
[[Category:Henry Draper Catalogue objects|216803]]
[[Category:Hipparcos objects|113283]]
[[Category:Bright Star Catalogue objects|8721]]
[[Category:Gliese and GJ objects|0879]]
[[Category:Durchmusterung objects|CD-32 17321]]
[[Category:Fomalhaut]]

Latest revision as of 23:47, 15 July 2024

TW Piscis Austrini
Location of TW Piscis Austrini (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Piscis Austrinus
Right ascension 22h 56m 24.05256s[1]
Declination −31° 33′ 56.0306″[1]
Apparent magnitude (V) 5.44–6.51[2]
Characteristics
Spectral type K5Vp[3]
U−B color index 1.02[4]
B−V color index 1.10[4]
Variable type BY Draconis[2]
Astrometry
Radial velocity (Rv)+6.79±0.12[1] km/s
Proper motion (μ) RA: 330.203 mas/yr[1]
Dec.: −158.602 mas/yr[1]
Parallax (π)131.5525 ± 0.0275 mas[1]
Distance24.793 ± 0.005 ly
(7.602 ± 0.002 pc)
Absolute magnitude (MV)7.08[5]
Details[6]
Mass0.704±0.016 M
Radius0.658±0.009 R
Luminosity0.19[5] L
Temperature4,610±67 K
Metallicity [Fe/H]−0.07±0.03 dex
Rotation10.3[7] days
Rotational velocity (v sin i)2.93[3] km/s
Age440[5] Myr
Other designations
TW PsA, Gl 879, HR 8721, CD−32°17321, HD 216803, LTT 9283, GCTP 5562.00, SAO 214197, CP(D)−32°6550, HIP 113283[8]
Database references
SIMBADdata
ARICNSdata

TW Piscis Austrini (also known as Fomalhaut B) is a main sequence star in the constellation Piscis Austrinus. It lies relatively close to the Sun, at an estimated distance of 24.8 light-years (7.6 parsecs). To an observer on Earth the star is visually separated from its larger companion Fomalhaut (A) by 2 degrees—the width of four full moons.[9]

A visual band light curve for TW Piscis Austrini, adapted from Busko and Torres (1978).[10] The error bar shown on the left-most point applies to all points.

The name TW Piscis Austrini is a variable star designation. This is a variable star of the type known as a BY Draconis variable, with surface brightness variations causing the changes as the star rotates. It varies slightly in apparent magnitude, ranging from 6.44 to 6.51 over a 10.3-day period.[2]

TW Piscis Austrini lies within a light-year of Fomalhaut.[11] Due to sharing the same proper motion, and the same estimated age of approximately 440 ± 40 million years, astronomers now consider them to be elements of a multiple star system.[5] A third star, dimmer and more widely separated, Fomalhaut C, gives the system the widest visual separation, to observers from Earth, at approximately 6 degrees.[9]

Planetary system

[edit]

In 2019, an exoplanet candidate around Fomalhaut B was detected by astrometry, but this remains unconfirmed.[12][13]

The Fomalhaut B planetary system[13]
Companion
(in order from star)
Mass Semimajor axis
(AU)
Orbital period
(years)
Eccentricity Inclination Radius
b (unconfirmed) 1.2+0.7
−0.6
MJ
25+52
−21

References

[edit]
  1. ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  2. ^ a b c Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: B/gcvs. Bibcode:2009yCat....102025S.
  3. ^ a b Demory, Brice-Olivier; Ségransan, Damien; Forveille, Thierry; Queloz, Didier; Beuzit, Jean-Luc; Delfosse, Xavier; Di Folco, Emmanuel; Kervella, Pierre; Le Bouquin, Jean-Baptiste; Perrier, Christian; Benisty, Myriam; Duvert, Gilles; Hofmann, Karl-Heinz; Lopez, Bruno; Petrov, Romain (October 2009). "Mass-radius relation of low and very low-mass stars revisited with the VLTI". Astronomy and Astrophysics. 505 (1): 205–215. arXiv:0906.0602. Bibcode:2009A&A...505..205D. doi:10.1051/0004-6361/200911976. S2CID 14786643.
  4. ^ a b Johnson, H. L.; Mitchell, R. I.; Iriarte, B.; Wisniewski, W. Z. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory. 4 (99): 99. Bibcode:1966CoLPL...4...99J.
  5. ^ a b c d Mamajek, E.E. (August 2012). "On the Age and Binarity of Fomalhaut". Astrophysical Journal Letters. 754 (2): L20. arXiv:1206.6353. Bibcode:2012ApJ...754L..20M. doi:10.1088/2041-8205/754/2/L20. S2CID 119191190.
  6. ^ Gomes da Silva, J.; Santos, N. C.; Adibekyan, V.; Sousa, S. G.; Campante, T. L.; Figueira, P.; Bossini, D.; Delgado-Mena, E.; Monteiro, M. J. P. F. G.; de Laverny, P.; Recio-Blanco, A.; Lovis, C. (2021-02-01). "Stellar chromospheric activity of 1674 FGK stars from the AMBRE-HARPS sample. I. A catalogue of homogeneous chromospheric activity". Astronomy and Astrophysics. 646: A77. arXiv:2012.10199. doi:10.1051/0004-6361/202039765. ISSN 0004-6361. Fomalhaut B's database entry at VizieR.
  7. ^ Mamajek, Eric E.; et al. (2013). "The Solar Neighborhood. XXX. Fomalhaut C". The Astronomical Journal. 146 (6): 154–163. arXiv:1310.0764. Bibcode:2013AJ....146..154M. doi:10.1088/0004-6256/146/6/154. S2CID 67821813.
  8. ^ "V* TW PsA -- Variable of BY Dra type". SIMBAD. Centre de Données astronomiques de Strasbourg. Retrieved 2010-01-20.
  9. ^ a b Bob King (2014-10-01). "Fomalhaut: A crazy-wide triple stat". Sky & Telescope. Retrieved 2020-06-13. Though it may appear isolated in the barren October sky, Fomalhaut has company. It feels the gravitational tug of the magnitude +6.5 star TW Piscis Austrini, 2° to the south. Both are 25 light-years distant and move in tandem across space, partaking of the same proper motion. They form a true double star with an actual separation of 5.5 trillion miles, or 0.91 light-year.
  10. ^ Busko, I. C.; Torres, C. A. O. (March 1978). "Flare activity by BY Draconis stars". Astronomy and Astrophysics. 64: 153–160. Bibcode:1978A&A....64..153B. Retrieved 23 February 2022.
  11. ^ Fred Schaaf (31 March 2008). The Brightest Stars: Discovering the Universe through the Sky's Most Brilliant Stars. Wiley. ISBN 978-0-470-24917-8.
  12. ^ Joe Rao (2019-09-23). "Fomalhaut, 'Royal' Star of Autumn, Swims with the Southern Fish". Space.com. Retrieved 2020-06-13. Believe it or not, an extrasolar planet might also be circling TW Piscis Austrini. NASA's Transiting Exoplanet Survey Satellite (TESS), a space telescope that's searching for planets around the brightest stars in Earth's night sky, recently found a possible candidate circling this star. It's almost the same size as our Earth, and orbits the star about every 10 days at a distance of 7.5 million miles from it.
  13. ^ a b De Rosa, Robert J.; Esposito, Thomas M.; Hirsch, Lea A.; Nielsen, Eric L.; Marley, Mark S.; Kalas, Paul; Wang, Jason J.; Macintosh, Bruce (7 October 2019). "The Possible Astrometric Signature of a Planetary-mass Companion to the Nearby Young Star TW Piscis Austrini (Fomalhaut B): Constraints from Astrometry, Radial Velocities, and Direct Imaging". Astronomical Journal. 158 (6): 225. arXiv:1910.02965. Bibcode:2019AJ....158..225D. doi:10.3847/1538-3881/ab4c9b. S2CID 203902656.
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