EX Lupi

{{Short description|T-Tauri star}} {{Starbox begin}} {{Starbox image | image = [[File:Ssc2009-11b.jpg|320px]] | caption = Artist's illustration of the disk around EX Lupi, showing the formation of silicate crystals | credit = }} {{Starbox observe | epoch = J2000.0 | constell = [[Lupus (constellation)|Lupus]] | ra = {{RA|16|03|05.491}}<ref name=GaiaEDR3/> | dec = {{DEC|−40|18|25.43}}<ref name=GaiaEDR3/> | appmag_v = }} {{Starbox character | type = [[Pre-main-sequence star|Pre-main-sequence]]<ref name=Sipos_et_al_2009/> | class = M0<ref name=Alcalá_et_al_2017/> | b-v = | u-b = | variable = [[YY Orionis star|YY Ori]]<ref name=Samus_et_al_2017/> }} {{Starbox astrometry | radial_v = {{val|−0.9|0.1}}<ref name=Sipos_et_al_2009/> | prop_mo_ra = −10.157 | prop_mo_dec = −22.531 | pm_footnote = <ref name=GaiaEDR3/> | parallax = 6.4634 | p_error = 0.0150 | parallax_footnote = <ref name=GaiaEDR3/> | absmag_v = }} {{Starbox detail | mass = 0.6<ref name=Sipos_et_al_2009/> | radius = 1.6<ref name=Sipos_et_al_2009/> | luminosity = 1.23{{±|0.53}}<ref name=Alcalá_et_al_2017/> | gravity = | temperature = 3,850{{±|177}}<ref name=Alcalá_et_al_2017/> | metal_fe = | rotation = | rotational_velocity = {{val|4.4|2.0}}<ref name=Sicilia-Aguilar_et_al_2015/> | age_myr = }} {{Starbox catalog | names = {{odlist | V=EX Lup | HD=325367 | IRAS=15597-4010 }},<ref name=SIMBAD/> HV 11976<ref name=McLaughlin1946/> }} {{Starbox reference | Simbad = HD+325367 }} {{Starbox end}}

'''EX Lupi''' is a young, single<ref name=Sipos_et_al_2009/> [[T-Tauri star]] in the southern [[constellation]] of [[Lupus (constellation)|Lupus]]. An [[irregular variable]],<ref name=Lehmann_et_al_1995/> it is the prototype of young, low-mass eruptive stars named '''EXors''',<ref name=Sipos_et_al_2009/> with ''EX Lupi'' being this object's [[variable star designation]]. At its minimal activity level, EX Lupi resembles a classical T-Tauri star of the [[M-type main-sequence star|M0 dwarf]] type.<ref name=Herbig_et_al_2001/> The low latitude of this star, at a declination of −40°, makes it difficult for northern observers to view.<ref name=Herbig_et_al_2001/> Based on [[stellar parallax|parallax]] measurements, it is located at a distance of about 505 [[light year]]s from the [[Sun]].<ref name=GaiaEDR3/> The star lies next to a gap in the Lupus cloud complex, a star forming region.<ref name=Herbig2007/>

During 1944, Edith M. Janssen at [[Harvard Observatory]] noticed a [[stellar spectrum]] that displayed bright lines on a photographic plate taken April 11, 1929, but these lines were missing on a spectrum from July 13, 1928. This star was found to be only two magnitudes fainter than at maximum, so a [[nova]] was ruled out. [[Dean Benjamin McLaughlin|D. B. McLaughlin]] then undertook a study of this object going as far back as 1893, finding further outbursts in 1901, 1914, 1925, 1929, 1934. Each time the brightness increased by about two magnitudes, followed by smaller, irregular fluctuations lasting 1–2 years before returning to a near constant minimum at magnitude 13.2.<ref name=McLaughlin1946/> Now designated EX Lupi, [[George Herbig]] studied the spectrum of this [[irregular variable]] in 1950, finding that it is similar to other [[emission-line]] stars associated with [[Dark nebula|nebulosity]].<ref name=Herbig1950/>

The next observed outburst was during the period 1955–1957 and was tracked by A. F. Jones. It reached a peak magnitude of 8.4, followed by a secondary brightening about 300 days later.<ref name=Herbig_et_al_2001/> After a period of quiescence during the 1980s, another eruptive burst was observed in March 1994.<ref name=Lehmann_et_al_1995/> It reached a peak magnitude of 11.5 on both April 30 and May 14.<ref name=Herbig_et_al_2001/> The cause was now understood to be the result of a mass accretion event with the infalling matter releasing its [[kinetic energy]] on the [[T-Tauri star]]. This creates a hot emission region that dominates the light output from the star. Many of the emission lines show an inverse [[P Cygni profile]], thereby demonstrating that it is coming from infalling material. [[Absorption line]]s in the spectrum show a redshift indicating a velocity of {{val|300|u=km/s}}.<ref name=Lehmann_et_al_1995/>

[[File:EXLupLightCurve.png|thumb|left|A [[Photometric_system#Photometric_letters|visual band]] [[light curve]] for EX Lupi, plotted from [[American Association of Variable Star Observers|AAVSO]] data<ref name="aavso"/>]] A major outburst of EX Lupi began in January 2008,<ref name=Jones2008/> and it reached a peak visual magnitude of 8 during February.<ref name=Ábrahám_et_al_2009/> It remained optically brighter by five magnitudes for a period of seven months.<ref name=Aspin_et_al_2010/> Infrared observations of the star's [[circumstellar disk]] during the outburst shows spectral features of crystalline [[silicate]]s, including strong indications of [[forsterite]]. The features resembled those seen in [[comet]]s and some [[protoplanetary disk]]s. The temperature of the disk is mostly below {{val|700|u=K}}, indicating a circumstellar dust-free inner hole with a radius of {{val|0.2|ul=AU}}.<ref name=Ábrahám_et_al_2009/> The disk may extend outward to at least {{val|150|u=AU}}. At stellar quiescence, the infrared silicate feature at a wavelength of {{val|10|u=μm}} can be explained as amorphous silicates of [[olivine]] and [[pyroxene]].<ref name=Sipos_et_al_2009/> Observations with [[Spitzer Space Telescope|Spitzer]] did showed an burst of cold [[Water vapor|water vapour]]. This is explained with enhanced ice sublimation due to a recession of the [[Frost line (astrophysics)|snowline]]. In 2022 and 2023 the cold water vapour is still unusually strong from [[James Webb Space Telescope|JWST]] spectra, showing that water freeze-out takes more than 10 years.<ref name="Smith2025"/>

Matter from the circumstellar disk is being accreted onto the star by means of accretion columns.<ref name=Sicilia-Aguilar_et_al_2015/> This column may be the cause of the 7.417 day [[radial velocity]] variations observed with this star. EX Lupi is accreting mass at a typical estimated rate of {{val|3.6|e=−8|ul=solar mass}}·yr<sup>−1</sup>, which can climb as high as {{val|e=−7|u=solar mass}}·yr<sup>−1</sup> during peak bursts.<ref name=Alcalá_et_al_2017/> Between outbursts, the star undergoes moderate variability of 1–2 magnitudes due to variations in the rate of accretion.<ref name=Sicilia-Aguilar_et_al_2015/>

==See also== * [[FU Orionis star]]

==References== <references>

<ref name=SIMBAD>{{cite simbad | title=HD 325367 | access-date=2022-01-29 | postscript=. | mode=cs2 }}</ref>

<ref name=Samus_et_al_2017>{{citation | last1=Samus | first1=N. N. | last2=Kazarovets | first2=E. V. | last3=Durlevich | first3=O. V. | last4=Kireeva | first4=N. N. | last5=Pastukhova | first5=E. N. | display-authors=1 | title=General Catalogue of Variable Stars | postscript=. | version=5.1 | journal=Astronomy Reports | date=2017 | volume=61 | issue=1 | pages=80–88 | doi=10.1134/S1063772917010085 | bibcode=2017ARep...61...80S | s2cid=125853869 }}</ref>

<ref name=McLaughlin1946>{{citation | title=The nova-like variable star HV 11976 | last=McLaughlin | first=Dean B. | journal=Astronomical Journal | postscript=. | volume=52 | page=109 | date=November 1946 | doi=10.1086/105935 | bibcode=1946AJ.....52..109M | doi-access=free }}</ref>

<ref name=Alcalá_et_al_2017>{{citation | title=X-shooter spectroscopy of young stellar objects in Lupus. Accretion properties of class II and transitional objects | last1=Alcalá | first1=J. M. | last2=Manara | first2=C. F. | last3=Natta | first3=A. | last4=Frasca | first4=A. | last5=Testi | first5=L. | last6=Nisini | first6=B. | last7=Stelzer | first7=B. | last8=Williams | first8=J. P. | last9=Antoniucci | first9=S. | last10=Biazzo | first10=K. | last11=Covino | first11=E. | last12=Esposito | first12=M. | last13=Getman | first13=F. | last14=Rigliaco | first14=E. | display-authors=1 | journal=Astronomy & Astrophysics | volume=600 | id=A20 | pages=42 | postscript=. | date=April 2017 | doi=10.1051/0004-6361/201629929 | arxiv=1612.07054 | bibcode=2017A&A...600A..20A | s2cid=119211262 }}</ref>

<ref name="aavso">{{cite web |title=Download Data |url=https://www.aavso.org/data-download |website=aavso.org |publisher=AAVSO |access-date=1 October 2021}}</ref>

<ref name=Herbig1950>{{citation | postscript=. | title=The Spectra of Five Irregular Variable Stars | last=Herbig | first=George H. | journal=Publications of the Astronomical Society of the Pacific | volume=62 | issue=367 | page=211 | date=October 1950 | doi=10.1086/126276 | bibcode=1950PASP...62..211H | s2cid=123120946 | doi-access=free}}</ref>

<ref name=Lehmann_et_al_1995>{{citation | postscript=. | title=The outburst of the T Tauri star EX LUPI in 1994 | display-authors=1 | last1=Lehmann | first1=T. | last2=Reipurth | first2=B. | last3=Brandner | first3=W. | journal=Astronomy and Astrophysics | volume=300 | page=L9 | date=August 1995 | arxiv=astro-ph/9506066 | bibcode=1995A&A...300L...9L }}</ref>

<ref name=Herbig_et_al_2001>{{citation | postscript=. | title=The 1993-1994 Activity of EX Lupi | display-authors=1 | last1=Herbig | first1=G. H. | last2=Aspin | first2=C. | last3=Gilmore | first3=Alan C. | last4=Imhoff | first4=Catherine L. | last5=Jones | first5=Albert F. | journal=The Publications of the Astronomical Society of the Pacific | volume=113 | issue=790 | pages=1547–1553 | date=December 2001 | doi=10.1086/324420 | bibcode=2001PASP..113.1547H | s2cid=121272736 }}</ref>

<ref name=Ábrahám_et_al_2009>{{citation | postscript=. | title=Episodic formation of cometary material in the outburst of a young Sun-like star | display-authors=1 | last1=Ábrahám | first1=P. | last2=Juhász | first2=A. | last3=Dullemond | first3=C. P. | last4=Kóspál | first4=Á. | last5=van Boekel | first5=R. | last6=Bouwman | first6=J. | last7=Henning | first7=Th. | last8=Moór | first8=A. | last9=Mosoni | first9=L. | last10=Sicilia-Aguilar | first10=A. | last11=Sipos | first11=N. | journal=Nature | volume=459 | issue=7244 | pages=224–226 | date=May 2009 | doi=10.1038/nature08004 | pmid=19444209 | arxiv=0906.3161 | bibcode=2009Natur.459..224A | s2cid=4426934 }}</ref>

<ref name=Jones2008>{{citation | postscript=. | title=EX Lupi | last=Jones | first=A. F. A. L. | journal=Central Bureau Electronic Telegrams | issue=1217 | editor-last=Green | editor-first=D. W. E. | date=January 2008 | page=1 | bibcode=2008CBET.1217....1J }}</ref>

<ref name=Aspin_et_al_2010>{{citation | postscript=. | title=The 2008 Extreme Outburst of the Young Eruptive Variable Star EX Lupi | last1=Aspin | first1=Colin | last2=Reipurth | first2=Bo | last3=Herczeg | first3=Gregory J. | last4=Capak | first4=Peter | display-authors=1 | journal=The Astrophysical Journal Letters | volume=719 | issue=1 | pages=L50–L55 | date=August 2010 | doi=10.1088/2041-8205/719/1/L50 | arxiv=1007.4178 | bibcode=2010ApJ...719L..50A | s2cid=2670001 }}</ref>

<ref name=Sipos_et_al_2009>{{citation | postscript=. | title=EX Lupi in quiescence | last1=Sipos | first1=N. | last2=Ábrahám | first2=P. | last3=Acosta-Pulido | first3=J. | last4=Juhász | first4=A. | last5=Kóspál | first5=Á. | last6=Kun | first6=M. | last7=Moór | first7=A. | last8=Setiawan | first8=J. | display-authors=1 | journal=Astronomy and Astrophysics | volume=507 | issue=2 | pages=881–889 | date=November 2009 | doi=10.1051/0004-6361/200911641 | arxiv=0906.3168 | bibcode=2009A&A...507..881S | s2cid=14365820 }}</ref>

<ref name=Sicilia-Aguilar_et_al_2015>{{citation | postscript=. | title=Accretion dynamics of EX Lupi in quiescence. The star, the spot, and the accretion column | last1=Sicilia-Aguilar | first1=Aurora | last2=Fang | first2=Min | last3=Roccatagliata | first3=Veronica | last4=Collier Cameron | first4=Andrew | last5=Kóspál | first5=Ágnes | last6=Henning | first6=Thomas | last7=Ábrahám | first7=Peter | last8=Sipos | first8=Nikoletta | display-authors=1 | journal=Astronomy & Astrophysics | volume=580 | id=A82 | pages=33 | date=August 2015 | doi=10.1051/0004-6361/201525970 | arxiv=1505.08011 | bibcode=2015A&A...580A..82S | s2cid=54725281 }}</ref>

<ref name=Herbig2007>{{citation | postscript=. | title=EX Lupi: History and Spectroscopy | last=Herbig | first=G. H. | journal=The Astronomical Journal | volume=133 | issue=6 | pages=2679–2683 | date=June 2007 | doi=10.1086/517494 | bibcode=2007AJ....133.2679H | s2cid=54092631 | doi-access=free}}</ref>

<ref name="Smith2025">{{Cite journal |last1=Smith |first1=Sarah A. |last2=Romero-Mirza |first2=Carlos E. |last3=Banzatti |first3=Andrea |last4=Rab |first4=Christian |last5=Ábrahám |first5=Péter |last6=Kóspál |first6=Ágnes |last7=Claes |first7=Rik |last8=Manara |first8=Carlo F. |last9=Öberg |first9=Karin I. |last10=Bouwman |first10=Jeroen |last11=de Miera |first11=Fernando Cruz-Sáenz |last12=Green |first12=Joel D. |date=May 2025 |title=JWST's Sharper View of EX Lup: Cold Water from Ice Sublimation during Accretion Outbursts |journal=The Astrophysical Journal |language=en |volume=984 |issue=2 |pages=L51 |arxiv=2504.13377 |bibcode=2025ApJ...984L..51S |doi=10.3847/2041-8213/adcab8 |doi-access=free |issn=0004-637X}}</ref>

</references>

==Further reading== {{Div col|small=yes}} *{{citation | postscript=. | title=Radio Observations of EX Lupi's disk post-outburst | last1=White | first1=J. | last2=Kospal | first2=A. | last3=Hughes | first3=A. | last4=Abraham | first4=P. | last5=Akimkin | first5=V. | last6=Banzatti | first6=A. | last7=Chen | first7=L. | last8=Cruz-Saenz De Miera | first8=F. | last9=Dutrey | first9=A. | last10=Flock | first10=M. | last11=Guilloteau | first11=S. | last12=Hales | first12=A. | last13=Henning | first13=T. | last14=Kadam | first14=K. | last15=Semenov | first15=D. | last16=Sicilia-Aguilar | first16=A. | last17=Teague | first17=R. | last18=Vorobyov | first18=E. | display-authors=1 | journal=Bulletin of the American Astronomical Society | volume=53 | issue=1 | id=2021n1i229p06 | date=January 2021 | bibcode=2021AAS...23722906W }} *{{citation | postscript=. | title=ALMA and VLA Observations of EX Lupi in Its Quiescent State | last1=White | first1=Jacob Aaron | last2=Kóspál | first2=Á. | last3=Hughes | first3=A. G. | last4=Ábrahám | first4=P. | last5=Akimkin | first5=V. | last6=Banzatti | first6=A. | last7=Chen | first7=L. | last8=Cruz-Sáenz de Miera | first8=F. | last9=Dutrey | first9=A. | last10=Flock | first10=M. | last11=Guilloteau | first11=S. | last12=Hales | first12=A. S. | last13=Henning | first13=T. | last14=Kadam | first14=K. | last15=Semenov | first15=D. | last16=Sicilia-Aguilar | first16=A. | last17=Teague | first17=R. | last18=Vorobyov | first18=E. I. | display-authors=1 | journal=The Astrophysical Journal | volume=904 | issue=1 | id=37 | pages=12 | date=November 2020 | doi=10.3847/1538-4357/abbb94 | arxiv=2009.14216 | bibcode=2020ApJ...904...37W | s2cid=222066744 | doi-access=free }} *{{citation | postscript=. | title=The circumstellar environment of EX Lupi: SPHERE and SINFONI views | last1=Rigliaco | first1=E. | last2=Gratton | first2=R. | last3=Kóspál | first3=Á. | last4=Mesa | first4=D. | last5=D'Orazi | first5=V. | last6=Ábrahám | first6=P. | last7=Desidera | first7=S. | last8=Ginski | first8=C. | last9=van Holstein | first9=R. G. | last10=Dominik | first10=C. | last11=Garufi | first11=A. | last12=Henning | first12=T. | last13=Menard | first13=F. | last14=Zurlo | first14=A. | last15=Baruffolo | first15=A. | last16=Maurel | first16=D. | last17=Blanchard | first17=P. | last18=Weber | first18=L. | display-authors=1 | journal=Astronomy & Astrophysics | volume=641 | id=A33 | pages=10 | date=September 2020 | doi=10.1051/0004-6361/202038337 | arxiv=2006.09787 | bibcode=2020A&A...641A..33R | s2cid=219720860 }} *{{citation | postscript=. | title=Depletion of Molecular Gas by an Accretion Outburst in a Protoplanetary Disk | display-authors=1 | last1=Banzatti | first1=A. | last2=Pontoppidan | first2=K. M. | last3=Bruderer | first3=S. | last4=Muzerolle | first4=J. | last5=Meyer | first5=M. R. | journal=The Astrophysical Journal Letters | volume=798 | issue=1 | id=L16 | pages=6 | date=January 2015 | doi=10.1088/2041-8205/798/1/L16 | arxiv=1412.1824 | bibcode=2015ApJ...798L..16B | s2cid=118659530 }} *{{citation | postscript=. | title=Radial velocity variations in the young eruptive star EX Lupi | last1=Kóspál | first1=Á. | last2=Mohler-Fischer | first2=M. | last3=Sicilia-Aguilar | first3=A. | last4=Ábrahám | first4=P. | last5=Curé | first5=M. | last6=Henning | first6=Th. | last7=Kiss | first7=Cs. | last8=Launhardt | first8=R. | last9=Moór | first9=A. | last10=Müller | first10=A. | display-authors=1 | journal=Astronomy & Astrophysics | volume=561 | id=A61 | pages=12 | date=January 2014 | doi=10.1051/0004-6361/201322428 | arxiv=1311.4177 | bibcode=2014A&A...561A..61K | s2cid=21725545 }} *{{citation | postscript=. | title=Detection of a Cool, Accretion-shock-generated X-Ray Plasma in EX Lupi during the 2008 Optical Eruption | last1=Teets | first1=William K. | last2=Weintraub | first2=David A. | last3=Kastner | first3=Joel H. | last4=Grosso | first4=Nicolas | last5=Hamaguchi | first5=Kenji | last6=Richmond | first6=Michael | display-authors=1 | journal=The Astrophysical Journal | volume=760 | issue=1 | id=89 | pages=10 | date=November 2012 | doi=10.1088/0004-637X/760/1/89 | arxiv=1210.1250 | bibcode=2012ApJ...760...89T | s2cid=119196162 }} *{{citation | postscript=. | title=Optical spectroscopy of EX Lupi during quiescence and outburst. Infall, wind, and dynamics in the accretion flow | display-authors=1 | last1=Sicilia-Aguilar | first1=A. | last2=Kóspál | first2=Á. | last3=Setiawan | first3=J. | last4=Ábrahám | first4=P. | last5=Dullemond | first5=C. | last6=Eiroa | first6=C. | last7=Goto | first7=M. | last8=Henning | first8=Th. | last9=Juhász | first9=A. | journal=Astronomy & Astrophysics | volume=544 | id=A93 | pages=48 | date=August 2012 | doi=10.1051/0004-6361/201118555 | arxiv=1206.3081 | bibcode=2012A&A...544A..93S | s2cid=54667372 }} *{{citation | postscript=. | title=EX Lupi from Quiescence to Outburst: Exploring the LTE Approach in Modeling Blended H2O and OH Mid-infrared Emission | display-authors=1 | last1=Banzatti | first1=A. | last2=Meyer | first2=M. R. | last3=Bruderer | first3=S. | last4=Geers | first4=V. | last5=Pascucci | first5=I. | last6=Lahuis | first6=F. | last7=Juhász | first7=A. | last8=Henning | first8=T. | last9=Ábrahám | first9=P. | journal=The Astrophysical Journal | volume=745 | issue=1 | id=90 | pages=16 | date=January 2012 | doi=10.1088/0004-637X/745/1/90 | arxiv=1111.2697 | bibcode=2012ApJ...745...90B | s2cid=119191359 }} *{{citation | postscript=. | title=Near-infrared Spectroscopy of EX Lupi in Outburst | display-authors=1 | last1=Kóspál | first1=Á. | last2=Ábrahám | first2=P. | last3=Goto | first3=M. | last4=Regály | first4=Zs. | last5=Dullemond | first5=C. P. | last6=Henning | first6=Th. | last7=Juhász | first7=A. | last8=Sicilia-Aguilar | first8=A. | last9=van den Ancker | first9=M. | journal=The Astrophysical Journal | volume=736 | issue=1 | id=72 | pages=11 | date=July 2011 | doi=10.1088/0004-637X/736/1/72 | arxiv=1105.1287 | bibcode=2011ApJ...736...72K | s2cid=53709972 }} *{{citation | postscript=. | title=Fundamental Vibrational Transition of CO During the Outburst of EX Lupi in 2008 | display-authors=1 | last1=Goto | first1=M. | last2=Regály | first2=Zs. | last3=Dullemond | first3=C. P. | last4=van den Ancker | first4=M. | last5=Brown | first5=J. M. | last6=Carmona | first6=A. | last7=Pontoppidan | first7=K. | last8=Ábrahám | first8=P. | last9=Blake | first9=G. A. | last10=Fedele | first10=D. | last11=Henning | first11=Th. | last12=Juhász | first12=A. | last13=Kóspál | first13=Á. | last14=Mosoni | first14=L. | last15=Sicilia-Aguilar | first15=A. | last16=Terada | first16=H. | last17=van Boekel | first17=R. | last18=van Dishoeck | first18=E. F. | last19=Usuda | first19=T. | journal=The Astrophysical Journal | volume=728 | issue=1 | id=5 | pages=13 | date=February 2011 | doi=10.1088/0004-637X/728/1/5 | arxiv=1012.5301 | bibcode=2011ApJ...728....5G | s2cid=41536954 }} *{{citation | postscript=. | title=A few days before the end of the 2008 extreme outburst of EX Lupi: accretion shocks and a smothered stellar corona unveiled by XMM-Newton | display-authors=1 | last1=Grosso | first1=N. | last2=Hamaguchi | first2=K. | last3=Kastner | first3=J. H. | last4=Richmond | first4=M. W. | last5=Weintraub | first5=D. A. | journal=Astronomy and Astrophysics | volume=522 | id=A56 | pages=10 | date=November 2010 | doi=10.1051/0004-6361/200913850 | arxiv=1007.2838 | bibcode=2010A&A...522A..56G | s2cid=55830181 }} *{{citation | postscript=. | display-authors=1 | title=Emission lines in EX Lup optical spectrum | last1=Sipos | first1=N. | last2=Abraham | first2=P. | last3=Acosta-Pulido | first3=J. | last4=Juhasz | first4=A. | last5=Kospal | first5=A. | last6=Kun | first6=M. | last7=Moor | first7=A. | last8=Setiawan | first8=J. | work=VizieR On-line Data Catalog: J/A+A/507/881 | date=October 2009 | doi=10.26093/cds/vizier.35070881 | bibcode=2009yCat..35070881S }} *{{citation | postscript=. | title=Optical Spectroscopy and Photometry of EX Lupi | last=Patten | first=B. M. | journal=Information Bulletin on Variable Stars | volume=4049 | number=1 | date=July 1994 | page=1 | bibcode=1994IBVS.4049....1P }} *{{citation | postscript=. | title=EX LUPI | last1=Jones | first1=A. F. | last2=Albrecht | first2=W. B. | last3=Gilmore | first3=A. C. | last4=Kilmartin | first4=P. M. | display-authors=1 | journal=IAU Circular | number=2 | date=May 1993 | page=2 | editor-last=Green | editor-first=D. W. E. | bibcode=1993IAUC.5791....2J }} *{{citation | postscript=. | title=The Photometric Range of EX Lupi: a Correction to IBVS 3755 | display-authors=1 | last1=Herbig | first1=G. H. | last2=Gilmore | first2=A. C. | last3=Suntzeff | first3=N. | journal=Information Bulletin on Variable Stars | volume=3808 | number=1 | date=November 1992 | page=1 | bibcode=1992IBVS.3808....1H }} *{{citation | postscript=. | title=Thirty-six years visual monitoring of the eruptive variable EX Lupi. | display-authors=1 | last1=Bateson | first1=F. M. | last2=McIntosh | first2=R. | last3=Brunt | first3=D. | publisher=Royal Astronomical Society of New Zealand - | journal=Publications of Variable Star Section | volume=16 | pages=49–65 | date=1991 | bibcode=1991PVSS...16...49B }} {{Div col end}}

[[Category:Red dwarfs]] [[Category:T Tauri stars]] [[Category:Eruptive variables]] [[Category:Circumstellar disks]] [[Category:Lupus (constellation)]] [[Category:Objects with variable star designations|Lupi, EX]]