Editing Canis Minor (section)

=== Stars ===
{{See also|List of stars in Canis Minor}}
[[Image:CanisMinorCC.jpg|thumb|right|300px|The constellation Canis Minor as it can be seen by the naked eye]]
Canis Minor contains only two stars brighter than fourth [[apparent magnitude|magnitude]]. At magnitude 0.34,<ref>{{cite web |url = http://simbad.u-strasbg.fr/simbad/sim-id?Ident=CCDM%20J07393%2B0514%20A |title = Procyon AB – Spectroscopic Binary |publisher = SIMBAD | access-date = 8 January 2013}}</ref> Procyon, or Alpha Canis Minoris, is the [[List of brightest stars|eighth-brightest star]] in the night sky, as well as one of the [[List of nearest stars|closest]]. Its name means "before the dog" or "preceding the dog" in Greek, as it rises an hour before the "Dog Star", [[Sirius]], of Canis Major. It is a [[binary star]] system, consisting of a yellow-white [[main-sequence]] star<ref name="ridpath">{{cite book |last1=Ridpath |first1=Ian |title=Stars and Planets Guide |last2=Tirion |first2=Wil |publisher=Princeton University Press |year=2001 |isbn=978-0-691-08913-3 |location=Princeton, New Jersey |pages=100–01 }}</ref> of [[spectral type]] F5&nbsp;IV-V, named Procyon&nbsp;A, and a faint [[white dwarf]] companion of spectral type DA, named Procyon&nbsp;B. Procyon&nbsp;B, which orbits the more massive star every 41 years, is of magnitude 10.7.<ref name="ridpath"/> Procyon&nbsp;A is 1.4 times the [[Sun's mass]], while its smaller companion is 0.6 times as massive as the Sun.<ref name=aj131>{{cite journal | last1=Gatewood | first1=George | last2=Han | first2=Inwoo | title=An Astrometric Study of Procyon | journal=Astronomical Journal | volume=131 | issue=2 | pages=1015–21 | year=2006 | doi=10.1086/498894 | bibcode=2006AJ....131.1015G | doi-access=free }}</ref> The system is {{convert|11.4|ly|pc|abbr=off|lk=on}} from [[Earth]], the shortest distance to a northern-hemisphere star of the first magnitude.<ref name="ridpath"/><ref>{{cite book |title = The Cambridge Encyclopedia of Stars |page = 63 |last = Kaler |first = James B. |authorlink=James B. Kaler |publisher = Cambridge University Press |year = 2006|location = Cambridge, England |isbn = 978-0-521-81803-2}}</ref> [[Gomeisa]], or Beta Canis Minoris, with a magnitude of 2.89, is the second-brightest star in Canis Minor. Lying {{convert|160 ± 10|ly|pc|abbr=off|lk=off}} from the [[Solar System]],<ref name=Gaia-DR2beta>{{cite DR2|3143264535611161088}}</ref> it is a blue-white main-sequence star of [[spectral class]] B8&nbsp;Ve.<ref name=betvar>{{cite web |url = https://www.aavso.org/vsx/index.php?view=detail.top&oid=5638 |title = Bet CMi |publisher = American Association of Variable Star Observers |work = International Variable Star Index |access-date = 13 January 2013 |date = 4 January 2010}}</ref> Although fainter to Earth observers, it is much brighter than Procyon, and is 250 times as [[Luminosity#Astronomy|luminous]] and three times as massive as the Sun.<ref name=Kalerbeta>{{Cite journal | first1=Jim | last1=Kaler | journal=Stars | title=Gomeisa (Beta Canis Minoris) | url=http://stars.astro.illinois.edu/sow/gomeisa.html | access-date=27 January 2012 }}</ref> Although its variations are slight, Gomeisa is classified as a [[shell star]] (Gamma Cassiopeiae variable), with a maximum magnitude of 2.84 and a minimum magnitude of 2.92.<ref name=betvar/> It is surrounded by a disk of gas which it heats and causes to emit radiation.<ref name=Kalerbeta/>

Johann Bayer used the Greek letters Alpha to Eta to label the most prominent eight stars in the constellation, designating two stars as Delta (named Delta<sup>1</sup> and Delta<sup>2</sup>).{{sfn|Wagman|2003|pp=76–77}} [[John Flamsteed]] numbered fourteen stars, discerning a third star he named Delta<sup>3</sup>;{{sfn|Wagman|2003|p=77}} his star 12 Canis Minoris was not found subsequently.{{sfn|Wagman|2003|p=369}} In Bayer's 1603 work ''[[Uranometria]]'', Procyon is located on the dog's belly, and Gomeisa on its neck.{{sfn|Wagman|2003|p=504}} [[Gamma Canis Minoris|Gamma]], [[Epsilon Canis Minoris|Epsilon]] and [[Eta Canis Minoris]] lie nearby,<ref name="kambic"/> marking the dog's neck, crown and chest, respectively.{{sfn|Wagman|2003|p=504}} Although it has an apparent magnitude of 4.34, Gamma Canis Minoris is an orange [[stellar classification|K-type]] [[giant star|giant]] of spectral class K3-III C, which lies {{convert|318|ly|pc|abbr=off|lk=off}} away.<ref>{{cite web |url = http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Gamma+Canis+Minoris&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = Gamma Canis Minoris |publisher = SIMBAD | access-date = 25 May 2012}}</ref> Its colour is obvious when seen through binoculars.<ref name="kambic">{{cite book|last=Kambič|first=Bojan |title=Viewing the Constellations with Binoculars: 250+ Wonderful Sky Objects to See and Explore|publisher=Springer|location=New York, New York|year=2009|page=32 | isbn = 978-0-387-85354-3 |url=https://books.google.com/books?id=3vxLNPNHOcwC&pg=PA233}}</ref> It is a multiple system, consisting of the [[spectroscopic binary]] Gamma A and three optical companions, Gamma B, magnitude 13; Gamma C, magnitude 12; and Gamma D, magnitude 10. The two components of Gamma A orbit each other every 389.2 days, with an eccentric orbit that takes their separation between 2.3 and 1.4 [[astronomical unit]]s (AU).<ref>{{cite web |url = http://stars.astro.illinois.edu/sow/gammacmi.html |title = Gamma Canis Minoris |last = Kaler |first = Jim |work = Star of the Week |access-date = 29 January 2013 |date = 19 March 2010}}</ref> Epsilon Canis Minoris is a yellow [[bright giant]] of spectral class G6.5IIb of magnitude of 4.99.<ref>{{cite web |url = http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Epsilon+Canis+Minoris&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = Epsilon Canis Minoris |publisher = SIMBAD | access-date = 25 May 2012}}</ref> It lies {{convert|730|-|810|ly|pc|abbr=off|lk=off}} from Earth,<ref name=Gaia-DR2eps>{{cite DR2|3155451625572457344}}</ref> with 13 times the diameter and 750 times the luminosity of the Sun.<ref name=bagnall>{{cite book |last=Bagnall |first=Philip M. |title=The Star Atlas Companion: What You Need to Know about the Constellations |publisher=Springer |location  =New York, New York |year=2012 |isbn=978-1-4614-0830-7 |pages=108–12|url=https://books.google.com/books?id=KcIg02TKW6QC&pg=PA110}}</ref> Eta Canis Minoris is a giant of spectral class F0III of magnitude 5.24,<ref>{{cite web |url = http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Eta+Canis+Minoris&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = Eta Canis Minoris |publisher = SIMBAD | access-date = 25 May 2012}}</ref> which has a yellowish hue when viewed through binoculars as well as a faint companion of magnitude 11.1.<ref name="garfinkle1997"/><ref>{{cite book |last1=Malin |first1=David |url=https://books.google.com/books?id=EQAYGmZT0o8C&pg=PA183 |title=Hartung's Astronomical Objects for Southern Telescopes: A Handbook for Amateur Observers |last2=Frew |first2=David J. |publisher=Cambridge University Press |year=1995 |isbn=978-0-521-55491-6 |location=Cambridge, England |page=184}}</ref> Located 4 [[arcsecond]]s from the primary, the companion star is actually around 440 AU from the main star and takes around 5,000 years to orbit it.<ref name="kalereta">{{cite web|url=http://stars.astro.illinois.edu/sow/etacmi.html|title=Eta and Delta-1 CMi |last=Kaler|first=Jim|work=Stars|publisher=University of Illinois|access-date=22 August 2012}}</ref>

Near Procyon, three stars share the name [[Delta Canis Minoris]]. [[Delta1 Canis Minoris|Delta<sup>1</sup>]] is a yellow-white [[stellar classification|F-type]] giant of magnitude 5.25 located around {{convert|790|ly|pc|abbr=off|lk=off}} from Earth. About 360 times as luminous and 3.75 times as massive as the Sun, it is expanding and cooling as it ages, having spent much of its life as a [[B-type main-sequence star|main sequence star]] of spectrum B6V.<ref name="kalereta"/> Also known as 8 Canis Minoris, [[Delta2 Canis Minoris|Delta<sup>2</sup>]] is an [[F-type main-sequence star]] of spectral type F2V and magnitude 5.59 which is {{convert|136|ly|pc|abbr=off|lk=off}} distant.<ref>{{cite web |url = http://simbad.u-strasbg.fr/simbad/sim-id?Ident=8+CMi |title = 8 Canis Minoris |publisher = SIMBAD | access-date = 13 January 2013}}</ref> The last of the trio, [[Delta3 Canis Minoris|Delta<sup>3</sup>]] (also known as 9 Canis Minoris), is a [[white main sequence star]] of spectral type A0Vnn and magnitude 5.83 which is {{convert|680 |ly|pc|abbr=off|lk=off}} distant.<ref>{{cite web |url = http://simbad.u-strasbg.fr/simbad/sim-id?Ident=9+CMi |title = 9 Canis Minoris |publisher = SIMBAD | access-date = 13 January 2013}}</ref> These stars mark the paws of the Lesser Dog's left hind leg, while magnitude 5.13 [[Zeta Canis Minoris|Zeta]] marks the right.{{sfn|Wagman|2003|p=504}}<ref name=simbadzeta/> A blue-white [[bright giant]] of spectral type B8II, Zeta lies around {{convert|623|ly|pc|abbr=off|lk=off}} away from the Solar System.<ref name=simbadzeta>{{cite web |url = http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Zeta+Canis+Minoris&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = Zeta Canis Minoris |publisher = SIMBAD | access-date = 6 September 2012}}</ref>

Lying 222 ± 7 light-years away with an apparent magnitude of 4.39,<ref name=Gaia-DR2lam>{{cite DR2|3087964941887693056}}</ref><ref name="exoplanet">{{cite encyclopedia|url=https://exoplanet.eu/catalog/hd_66141_b--1222/|title = Planet HD 66141 b|last=Zolotukhin|first=Ivan|year=2012|encyclopedia=[[Extrasolar Planets Encyclopaedia]]|access-date=21 December 2012}}</ref> [[HD 66141]] is 6.8&nbsp;billion years old and has [[Stellar evolution#Mid-sized stars|evolved]] into an orange giant of spectral type K2III with a diameter around 22 times that of the Sun, and weighing 1.1 solar masses. It is 174 times as luminous as the Sun, with an [[absolute magnitude]] of −0.15.<ref name="Lee">{{Cite journal |title=Detection of an Exoplanet Around the Evolved K Giant HD 66141 |arxiv=1211.2054 |year=2012|journal=Astronomy & Astrophysics|volume=548|doi=10.1051/0004-6361/201118014 |author1=Lee, B.-C. |author2=Mkrtichian, D. E. |author3=Han, I. |author4=Park, M.-G. |author5=Kim, K.-M. |pages=A118|bibcode = 2012A&A...548A.118L |s2cid=54984721 }}</ref> HD 66141 was mistakenly named 13 Puppis, as its celestial coordinates were recorded incorrectly when catalogued and hence mistakenly thought to be in the constellation of [[Puppis]]; Bode gave it the name Lambda Canis Minoris, which is now obsolete.{{sfn|Wagman|2003|p=460}} The orange giant is orbited by a planet, [[HD 66141b]], which was detected in 2012 by measuring the star's [[radial velocity]]. The planet has a mass around 6 times that of [[Jupiter]] and a [[orbital period|period]] of 480 days.<ref name="exoplanet"/>

A [[red giant]] of spectral type M4III, [[BC Canis Minoris]] lies around {{convert|500|ly|pc|abbr=off|lk=off}} distant from the Solar System.<ref name="Tabur">{{cite journal | title=Long-term Photometry and Periods for 261 Nearby Pulsating M Giants | last1=Tabur |first1 =V. |last2=Bedding |first2=T. R. |year=2009 |journal=[[Monthly Notices of the Royal Astronomical Society]] |volume= 400 | issue =4 |pages= 1945–61 |doi=10.1111/j.1365-2966.2009.15588.x | last3=Kiss | first3=L. L. | last4=Moon | first4=T. T. | last5=Szeidl | first5=B. | last6=Kjeldsen | first6=H. | doi-access=free |arxiv = 0908.3228 |bibcode = 2009MNRAS.400.1945T | s2cid=15358380 }}</ref> It is a [[semiregular variable star]] that varies between a maximum magnitude of 6.14 and minimum magnitude of 6.42.<ref>{{cite web |url = https://www.aavso.org/vsx/index.php?view=detail.top&oid=5595 |title = BC CMi |publisher = American Association of Variable Star Observers |work = International Variable Star Index |access-date = 13 January 2013 |date = 25 August 2009}}</ref> Periods of 27.7, 143.3 and 208.3 days have been recorded in its pulsations.<ref name="Tabur"/> [[AZ Canis Minoris|AZ]], [[AD Canis Minoris|AD]] and [[BI Canis Minoris]] are [[Delta Scuti variable]]s—short period (six hours at most) pulsating stars that have been used as [[standard candles]] and as subjects to study [[astroseismology]].<ref>{{cite web|url=https://www.aavso.org/vsots_delsct|title=Delta Scuti and the Delta Scuti Variables|last=Templeton|first=Matthew |date=16 July 2010|work=Variable Star of the Season|publisher=AAVSO (American Association of Variable Star Observers)|access-date=3 November 2012}}</ref> AZ is of spectral type A5IV,<ref>{{cite web |url = http://simbad.u-strasbg.fr/simbad/sim-id?Ident=AZ+Canis+Minoris&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = V* AZ Canis Minoris – Variable of Delta Scuti type |publisher = SIMBAD | access-date = 1 October 2012}}</ref> and ranges between magnitudes 6.44 and 6.51 over a period of 2.3 hours.<ref>{{cite web |url = https://www.aavso.org/vsx/index.php?view=detail.top&oid=5593 |title = AZ CMi |publisher = AAVSO |work = International Variable Star Index |access-date = 14 January 2013 |date = 4 January 2010}}</ref> AD has a spectral type of F2III,<ref>{{cite web |url = http://simbad.u-strasbg.fr/simbad/sim-id?Ident=AD+Canis+Minoris&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = V* AD Canis Minoris – Variable of Delta Scuti type |publisher = SIMBAD | access-date = 1 October 2012}}</ref> and has a maximum magnitude of 9.21 and minimum of 9.51, with a period of approximately 2.95 hours.<ref>{{cite web |url = https://www.aavso.org/vsx/index.php?view=detail.top&oid=5572 |title = AD Canis Minoris |publisher = AAVSO |work = International Variable Star Index |access-date = 17 January 2013 |date = 4 January 2010}}</ref> BI is of spectral type F2 with an apparent magnitude varying around 9.19<ref>{{cite web |url = http://simbad.u-strasbg.fr/simbad/sim-id?Ident=BI+Canis+Minoris&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = V* BI Canis Minoris – Variable of Delta Scuti type |publisher = SIMBAD | access-date = 1 October 2012}}</ref> and a period of approximately 2.91 hours.<ref>{{cite web |url = https://www.aavso.org/vsx/index.php?view=detail.top&oid=5601 |title = BI Canis Minoris |publisher = AAVSO |work = International Variable Star Index |access-date = 17 January 2013 |date = 2 February 2011}}</ref>

At least three red giants are [[Mira variable]]s in Canis Minor. [[S Canis Minoris]], of spectral type M7e,<ref>{{cite web |url = http://simbad.u-strasbg.fr/simbad/sim-id?Ident=S+Canis+Minoris&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = S Canis Minoris |publisher = SIMBAD | access-date = 27 August 2012}}</ref> is the brightest, ranging from magnitude 6.6 to 13.2 over a period of 332.94 days.<ref name="garfinkle1997"/><ref>{{cite web |url = https://www.aavso.org/vsx/index.php?view=detail.top&oid=5516 |title = S CMi |publisher = AAVSO |work = International Variable Star Index |access-date = 14 January 2013 |date = 4 January 2010}}</ref> [[V Canis Minoris]] ranges from magnitude 7.4 to 15.1 over a period of 366.1 days. Similar in magnitude is [[R Canis Minoris]], which has a maximum of 7.3, but a significantly brighter minimum of 11.6. An [[S-type star]], it has a period of 337.8 days.<ref>{{cite book |title = Patrick Moore's Data Book of Astronomy |last1 = Moore |first1 = Patrick |authorlink1 = Patrick Moore |last2 = Rees |first2 = Robin |page=396 |isbn = 978-0-521-89935-2 |publisher = Cambridge University Press |year = 2011}}</ref>

[[YZ Canis Minoris]] is a [[red dwarf]] of spectral type M4.5V and magnitude 11.2,<ref>{{cite web |url = http://simbad.u-strasbg.fr/simbad/sim-id?Ident=YZ+Canis+Minoris&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = V* YZ Canis Minoris – Variable of BY Draconis Type |publisher = SIMBAD | access-date = 1 October 2012}}</ref> roughly three times the size of Jupiter and {{convert|20|ly|pc|abbr=off|lk=off}} from Earth. It is a [[flare star]], emitting unpredictable outbursts of energy for mere minutes, which might be much more powerful analogues of [[solar flare]]s.<ref name="First flares">{{cite journal|title=First Flares on a Distant Star|journal=New Scientist|date=4 February 1982 |page=305|url=https://books.google.com/books?id=XQwcxTIERmUC&pg=PA305}}</ref> [[Luyten's Star]] (GJ 273) is a red dwarf star of spectral type M3.5V and close neighbour of the Solar System. Its visual magnitude of 9.9 renders it too faint to be seen with the naked eye,<ref name="RECONS">{{cite web|title=The One Hundred Nearest Stars |date=1 January 2012 |publisher=Georgia State University Astronomy |url=http://www.chara.gsu.edu/RECONS/TOP100.posted.htm |access-date=1 October 2012 |location=Atlanta, Georgia |url-status=dead |archive-url=https://web.archive.org/web/20120513202710/http://www.chara.gsu.edu/RECONS/TOP100.posted.htm |archive-date=13 May 2012 }}</ref> even though it is only {{convert|12.39|ly|pc|abbr=off}} away.<ref>{{cite web |url = http://simbad.u-strasbg.fr/simbad/sim-id?Ident=GJ+273&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = LHS 33 – High Proper-motion Star |publisher = SIMBAD | access-date = 5 October 2012}}</ref> Fainter still is [[PSS 544-7]], an eighteenth-magnitude red dwarf around 20 per cent the mass of the Sun, located {{convert|685|ly|pc|abbr=off|lk=off}} from Earth. First noticed in 1991, it is thought to be a cannonball star, shot out of a star cluster and now moving rapidly through space directly away from the [[galactic disc]].<ref>{{cite journal |first1=Carlos |last1=de la Fuente Marcos |last2=de la Fuente Marcos |first2=Raúl |title=A Cannonball Star Candidate in Canis Minor |journal=New Astronomy |volume=10 |issue=7 |pages=551–59 |doi=10.1016/j.newast.2005.04.001 |year=2005 |bibcode = 2005NewA...10..551D }}</ref>

The [[WZ Sagittae]]-type [[dwarf nova]] [[DY Canis Minoris]] (also known as [[VSX J074727.6+065050]]) flared up to magnitude 11.4 over January and February 2008 before dropping eight magnitudes to around 19.5 over approximately 80 days. It is a remote binary star system where a white dwarf and low-mass star orbit each other close enough for the former star to draw material off the latter and form an [[accretion disc]]. This material builds up until it erupts dramatically.<ref>{{cite journal|author1=Shears, Jeremy |author2=Brady, Steve |author3=Bolt, Greg |author4=Campbell, Tut |author5=Collins, Donald F. |author6=Cook, Lewis M. |author7=Crawford, Timothy R. |author8=Koff, Robert |author9=Krajci, Tom |author10=McCormick, Jennie |author11=Nelson, Peter |author12=Patterson, Joseph |author13=Ponthière, Pierre de |author14=Potter, Mike |author15=Rea, Robert |author16=Roberts, George |author17=Sabo, Richard |author18=Staels, Bart |author19=Vanmunster, Tonny |year=2009|title=VSX J074727.6+065050: A New WZ Sagittae Star in Canis Minor |journal=Journal of the British Astronomical Association|volume=119|issue=6|pages=340–46 |arxiv = 0905.0061 |bibcode = 2009JBAA..119..340S }}</ref>