View source for Denebola

{{Short description|Third brightest star in the Leo constellation}}
{{About|the star|other uses|Denebola (disambiguation)}}
{{distinguish|text=[[Deneb]], a star in the constellation Cygnus}}
{{Starbox begin
 | name    = Denebola
}}
{{Starbox image
 | image=
{{Location mark
|image=Leo constellation map.svg|alt=|float=center|width=280
|label=|position=right
|mark=Red circle.svg|mark_width=12|mark_link=Beta Leonis|x=89|y=523
}}
|caption=Location of β Leonis (circled)
}}
{{Starbox observe
| epoch    = J2000
| ra       = {{RA|11|49|03.57834}}<ref name=aaa474_2_653/>
| dec      = {{DEC|+14|34|19.4090}}<ref name=aaa474_2_653/>
| appmag_v = 2.14<ref name=gcvs/>
| constell = [[Leo (constellation)|Leo]]
| pronounce = {{IPAc-en|d|@|'|n|E|b|@|l|@}},<ref>{{MW|Denebola}}</ref>
}}
{{Starbox character
| class    = A3Va<ref name=gray/>
| b-v      = +0.09<ref name=hr/>
| u-b      = +0.07<ref name=hr/>
| variable = [[Delta Scuti variable|δ Sct]]<ref name=gcvs/>
}}
{{Starbox astrometry
| radial_v = −0.2<ref name=rgcrv/>
| prop_mo_ra  = −497.68<ref name=aaa474_2_653/>
| prop_mo_dec = −114.67<ref name=aaa474_2_653/>
| parallax = 90.91
| p_error  = 0.52
| parallax_footnote = <ref name=aaa474_2_653/>
| absmag_v = +1.93<ref name=Anderson2012/>
}}
{{Starbox detail
| mass     = 1.78<ref name="aaa426"/>
| radius   = {{val|1.75|0.02}}<ref name="2023AJ....166..268B"/>
| luminosity  = {{val|12.9|0.1}}<ref name="2023AJ....166..268B"/>
| temperature = {{val|fmt=commas|8262|36}}<ref name="2023AJ....166..268B"/>
| gravity  = 4.0<ref name="aaa427"/>
| metal_fe = +0.00<ref name="aaa426"/>
| rotational_velocity = 128<ref name=aaa463_2_671/>
| age_myr   = 100–380<ref name="aaa426"/>
}}
{{Starbox catalog
| names = {{odlist | name=Deneb Aleet | B=β Leonis | F=94 Leo | BD=+15°2383 | FK5=444 | GCTP=2738.00 | GJ=448 | HD=102647 | HIP=57632 | HR=4534 | LHS=2462 | LTT=13249 | SAO=99809 }}<ref name="SIMBAD" /><ref name=alcyone/>
}}
{{Starbox reference
| Simbad = DENEBOLA
}}
{{Starbox end}}

'''Denebola''' is the [[List of stars in Leo|third-brightest star]] in the [[zodiac]] [[constellation]] of [[Leo (constellation)|Leo]]. It is the easternmost of the bright stars of Leo. It has the [[Bayer designation]] '''Beta Leonis''' or '''β Leonis''', which are abbreviated '''Beta Leo''' or '''β Leo'''. Denebola is an [[A-type main sequence star]] with 75% more mass than the [[Sun]] and 15 times the Sun's luminosity. Based on [[parallax]] measurements from the [[Hipparcos]] astrometry satellite, the star is at a distance of {{convert|36|ly|pc|abbr=off|lk=on}} from the Sun. Its [[apparent visual magnitude]] is 2.14, making it readily visible to the naked eye. Denebola is a [[Delta Scuti variable|Delta Scuti type]] [[variable star]], meaning its luminosity varies very slightly over a period of a few hours.

==Nomenclature==
[[File:LeoCC.jpg|left|thumb|upright=1.05|Denebola is the most eastward (left) bright star in this stick-figure diagram overlaid on a constellation photograph of Leo]]
''β Leonis'' ([[Latinisation of names|Latinised]] to ''[[beta (letter)|Beta]] Leonis'') is the star's [[Bayer designation]]. In [[Johann Bayer]]'s ''[[Uranometria]]'' (1603), it  was designated β (Beta) as the second-brightest star in the constellation. It also bears the [[Flamsteed designation]] of ''94 Leonis'' (assigned on the basis of increasing [[right ascension]] rather than luminosity) and additional designations followed as the star was recorded in subsequent [[star catalogue]]s.

The traditional name ''Denebola'' is shortened from ''{{Transliteration|ar|Deneb Alased}}'', from the [[Arabic]] phrase ''{{lang|ar|ذنب الاسد}}'' ''{{Transliteration|ar|ðanab al-asad}}'' 'tail of the lion', as it represents the lion's tail, the star's position in the Leo constellation.<ref name=allen1963/> ([[Deneb]] in [[Cygnus (constellation)|Cygnus]] has a similar name origin.) In the ''Alphonsine Tables'' it was recorded as Denebalezeth.<ref name=Kunitzsch86/> On [[Richard Anthony Proctor|R. A. Proctor]]'s 1871 star chart of the [[Northern Hemisphere]] it was designated ''Deneb Aleet''. In 2016, the [[International Astronomical Union]] organized a [[IAU Working Group on Star Names|Working Group on Star Names]] (WGSN)<ref name="WGSN"/> to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016<ref name="WGSN1"/> included a table of the first two batches of names approved by the WGSN, which included ''Denebola'' for this star. It is now so entered in the IAU Catalog of Star Names.<ref name="IAU-CSN"/>

15th century astronomer [[Ulugh Beg]], gives the name ''Al Ṣarfah'', the Changer (i.e. of the weather), as the star's individual title.<ref name=allen/> [[Al-Biruni]], a Muslim scholar and polymath of the 11th century, wrote of it: "The heat turns away when it rises, and the cold turns away when it disappears."<ref name=allen/>

Ancient Chinese astronomers designated it the first star of the five-star asterism "Seat of the Five Emperors", hence its [[Chinese star names|Chinese name]] 五帝座一 (''Wǔdìzuò-yī'').

In [[Hindu]] [[Hindu calendar|astronomy]], Denebola corresponds to the [[Nakshatra]] (a sector along the [[ecliptic]]) named ''Uttara Phalgunī'' (second reddish one).

Denebola, along with [[Spica]] and [[Arcturus]], is part of the [[Spring Triangle]] asterism, and by extension, also of the [[Great Diamond]] together with the star [[Cor Caroli]].<ref name=triangle/>

==Properties==
Denebola is a relatively young star with an age estimated at less than 400&nbsp;million years. Interferometric observations give a radius that is about 173% that of the Sun. Its high rate of rotation results in an oblate shape with an [[equatorial bulge]]. It has 75% more mass than the Sun, which results in a much higher overall luminosity and a shorter life span on the [[main sequence]].<ref name="aaa426" />

Based upon the star's [[stellar spectrum|spectrum]], it has a [[stellar classification]] of A3&nbsp;Va,<ref name=gray/> with the [[luminosity class]] 'Va' indicating this is a particularly luminous dwarf, a [[main sequence]] star that is generating energy through the [[nuclear fusion]] of hydrogen at its core. The [[effective temperature]] of Denebola's outer envelope is about {{val|fmt=commas|8,500|ul=K}}, which results in the white hue typical of [[Stellar classification#Class A|A-type stars]]. Denebola has a high [[stellar rotation|projected rotational velocity]] of 128&nbsp;km/s, which is of the same [[order of magnitude]] as for the very rapidly rotating star [[Achernar]]. The Sun, in comparison, has an equatorial rotation velocity of 2&nbsp;km/s.<ref name="aaa427" /> This star is believed to be a [[Delta Scuti variable]] star that exhibits fluctuations in luminosity of 0.025 magnitudes roughly ten times per day.<ref name="mkrtichian" />

Denebola shows a strong [[infrared excess]], indicating there is a circumstellar [[debris disk]] of cool dust in orbit around it.<ref name=aaa181_1_77/> This dust has a temperature of about {{convert|120|K|°C|abbr=on}}. Observations with the [[Herschel Space Observatory]] have provided resolved images, which show the disk to be located at a mean radius of 39&nbsp;[[astronomical unit]]s from the star.<ref name=aaa518_L135/>  As the [[Solar System]] is believed to have formed out of such a disk, Denebola and similar stars such as [[Vega]] and [[Beta Pictoris]] may be candidate locations for [[extrasolar planet]]s.

[[Kinematic]] studies have shown that Denebola is part of a [[stellar association]] dubbed the [[IC 2391]] supercluster. All the stars of this group share a roughly common motion through space, although they are not gravitationally bound. This suggests that they were born in the same location, and perhaps initially formed an [[open cluster]]. Other stars in this association include [[Alpha Pictoris]], [[Beta Canis Minoris]] and the [[open cluster]] IC 2391. In total more than sixty probable members of the group have been identified.<ref name=aj102_2028/>

==See also==
*[[List of nearest bright stars]]

==References==
{{reflist|30em|refs=

<ref name="IAU-CSN">{{cite web | url=http://www.pas.rochester.edu/~emamajek/WGSN/IAU-CSN.txt | title=IAU Catalog of Star Names |access-date=28 July 2016}}</ref>

<ref name="WGSN">{{cite web | url=https://www.iau.org/science/scientific_bodies/working_groups/280/ | title=IAU Working Group on Star Names (WGSN)|access-date=22 May 2016}}</ref>

<ref name="WGSN1">{{cite web | url=http://www.pas.rochester.edu/~emamajek/WGSN/WGSN_bulletin1.pdf | title=Bulletin of the IAU Working Group on Star Names, No. 1 |access-date=28 July 2016}}</ref>

<ref name=triangle>{{cite web
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 | url=http://www.space.com/16085-spring-triangle-stars-skywatching.html
 | access-date=2024-01-29 | archive-date=2023-05-29 | url-status=live
 | archive-url=https://web.archive.org/web/20230529185448/https://www.space.com/16085-spring-triangle-stars-skywatching.html }}</ref>

<ref name=Kunitzsch86>{{cite journal|last=Kunitzsch|first=Paul|year=1986|title=The Star Catalogue Commonly Appended to the Alfonsine Tables|journal=Journal for the History of Astronomy|volume=17|issue=49|pages=89–98|bibcode = 1986JHA....17...89K |doi=10.1177/002182868601700202|s2cid=118597258}}</ref>

<ref name=hr>{{cite book |editor-last1=Hoffleit |editor-first1=D. |editor-link1=Ellen Dorrit Hoffleit |editor-last2=Jaschek |editor-first2=C. |editor-link2=Carlos Jaschek |year=1991 |title=The Bright Star Catalogue |location=New Haven |publisher=Yale University Observatory |bibcode=1991bsc..book.....H}}</ref>

<ref name=gcvs>{{cite journal
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 | title=General Catalogue of Variable Stars
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<ref name=aaa474_2_653>{{cite journal | first=F. | last=van Leeuwen |date=November 2007 | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 |arxiv = 0708.1752 | s2cid=18759600 }}</ref>

<ref name=Anderson2012>{{cite journal
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 | arxiv=1108.4971 | s2cid=119257644 }}</ref>

<ref name="mkrtichian">{{cite conference | last1=Mkrtichian | first1=D. E. | last2=Yurkov | first2=A. | title=β Leo - Back to Delta Scuti Stars? | book-title=Proceedings of the 20th Stellar Conference of the Czech and Slovak Astronomical Institutes | pages=172 | publisher=Dordrecht, D. Reidel Publishing Co. | date=5–7 November 1997 | location=Brno, Czech Republic | bibcode=1998vsr..conf..143M | isbn=80-85882-08-6 }}</ref>

<ref name="aaa426">{{cite journal | display-authors=1 | last1=Di Folco | first1=E. | last2=Thévenin | first2=F. | last3=Kervella | first3=P. | last4=Domiciano de Souza | first4=A. | last5=Coudé du Foresto | first5=V. | last6=Ségransan | first6=D. | last7=Morel | first7=P. | title=VLTI near-IR interferometric observations of Vega-like stars | journal=Astronomy and Astrophysics | year=2004 | volume=426 | issue=2 | pages=601–617 | bibcode=2004A&A...426..601D | doi=10.1051/0004-6361:20047189 | doi-access=free }}</ref>

<ref name="aaa427">{{cite journal | last1=Acke | first1=B. | last2=Waelkens | first2=C. | title=Chemical analysis of 24 dusty (pre-)main sequence stars | journal=Astronomy and Astrophysics | year=2004 | volume=427 | issue=3 | pages=1009–1017 | arxiv=astro-ph/0408221 | doi=10.1051/0004-6361:20041460| bibcode=2004A&A...427.1009A | s2cid=16615394 }}</ref>

<ref name=rgcrv>{{cite conference | last=Evans | first=D. S. | date=June 20–24, 1966 | editor1=Batten, Alan Henry | editor2= Heard, John Frederick | contribution=The Revision of the General Catalogue of Radial Velocities | volume=30 | pages=57 | title=Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30 | location=University of Toronto | publisher=International Astronomical Union | bibcode=1967IAUS...30...57E }}</ref>

<ref name=aaa463_2_671>{{cite journal | last1=Royer | first1=F. | last2=Zorec | first2=J. | last3=Gómez | first3=A. E. | title=Rotational velocities of A-type stars. III. Velocity distributions | journal=Astronomy and Astrophysics | volume=463 | issue=2 | pages=671–682 |date=February 2007 | doi=10.1051/0004-6361:20065224 | bibcode=2007A&A...463..671R |arxiv = astro-ph/0610785 | s2cid=18475298 }}</ref>

<ref name="SIMBAD">{{cite simbad | title=* bet Leo | access-date= 2007-06-18 }}</ref>

<ref name=alcyone>{{cite web | url=http://www.alcyone.de/SIT/mainstars/SIT000544.htm | title=Denebola | publisher=Alcyone | access-date=2006-08-10 }}</ref>

<ref name=aaa181_1_77>{{cite journal | last=Cote | first=J. | title=B and A type stars with unexpectedly large colour excesses at IRAS wavelengths | journal=Astronomy and Astrophysics | year=1987 | volume=181 | issue=1 | pages=77–84 | bibcode=1987A&A...181...77C }}</ref>

<ref name=aaa518_L135>{{cite journal | display-authors=1 | last1=Matthews | first1=B. C. | last2=Sibthorpe | first2=B. | last3=Kennedy | first3=G. | last4=Phillips | first4=N. | last5=Churcher | first5=L. | last6=Duchêne | first6=G. | last7=Greaves | first7=J. S. | last8=Lestrade | first8=J.-F. | last9=Moro-Martin | first9=A. | last10=Wyatt | first10=M. C. | last11=Bastien | first11=P. | last12=Biggs | first12=A. | last13=Bouvier | first13=J. | last14=Butner | first14=H. M. | last15=Dent | first15=W. R. F. | last16=Di Francesco | first16=J. | last17=Eislöffel | first17=J. | last18=Graham | first18=J. | last19=Harvey | first19=P. | last20=Hauschildt | first20=P. | last21=Holland | first21=W. S. | last22=Horner | first22=J. | last23=Ibar | first23=E. | last24=Ivison | first24=R. J. | last25=Johnstone | first25=D. | last26=Kalas | first26=P. | last27=Kavelaars | first27=J. | last28=Rodriguez | first28=D. | last29=Udry | first29=S. | last30=Van Der Werf | first30=P. | title=Resolving debris discs in the far-infrared: Early highlights from the DEBRIS survey | journal=Astronomy and Astrophysics | year=2010 | volume=518 | pages=L135 | doi=10.1051/0004-6361/201014667 | bibcode=2010A&A...518L.135M | arxiv=1005.5147 | s2cid=54013449 }}</ref>

<ref name=aj102_2028>{{cite journal | last=Eggen | first=O. J. | title=The IC 2391 supercluster | journal=Astronomical Journal | year=1991 | volume=102 | pages=2028–2040 | bibcode=1991AJ....102.2028E | doi=10.1086/116025 }}</ref>

<ref name=allen1963>{{cite book | last=Allen | first=R. H. | year=1963 | author-link=Richard Hinckley Allen | title=Star Names: Their Lore and Meaning | url=https://archive.org/details/starnamestheirlo00alle/page/258 | access-date=2010-12-12 | edition=Reprint | publisher=Dover Publications Inc | location=New York, NY | isbn=0-486-21079-0 | page=[https://archive.org/details/starnamestheirlo00alle/page/258 258] | url-access=registration }}</ref>

<ref name=gray>{{cite journal|bibcode=2003AJ....126.2048G|title=Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I|journal=The Astronomical Journal|volume=126|issue=4|pages=2048|last1=Gray|first1=R. O.|last2=Corbally|first2=C. J.|last3=Garrison|first3=R. F.|last4=McFadden|first4=M. T.|last5=Robinson|first5=P. E.|year=2003|doi=10.1086/378365|arxiv = astro-ph/0308182 |s2cid=119417105}}</ref>

<ref name="2023AJ....166..268B">
{{cite journal
 | last1=Baines | first1=Ellyn K.
 | last2=Clark III | first2=James H.
 | last3=Schmitt | first3=Henrique R.
 | last4=Stone | first4=Jordan M.
 | last5=von Braun | first5=Kaspar
 | title=33 New Stellar Angular Diameters from the NPOI, and Nearly 180 NPOI Diameters as an Ensemble
 | journal=The Astronomical Journal
 | volume=166 | issue=6 | page=268 | date=2023-12-01
 | bibcode=2023AJ....166..268B
 | doi=10.3847/1538-3881/ad08be
 | doi-access=free
 | issn=0004-6256
}}</ref>

<ref name=allen>{{cite web |url=https://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Leo*.html |title=LacusCurtius • Allen's Star Names — Leo |access-date=2024-06-02 }}</ref>

}}

==Further reading==
{{Div col|small=yes}}
*{{cite journal
 | title=The HOSTS Survey: Evidence for an Extended Dust Disk and Constraints on the Presence of Giant Planets in the Habitable Zone of β Leo
 | last1=Defrère | first1=D. | last2=Hinz | first2=P. M.
 | last3=Kennedy | first3=G. M. | last4=Stone | first4=J.
 | last5=Rigley | first5=J. | last6=Ertel | first6=S.
 | last7=Gaspar | first7=A. | last8=Bailey | first8=V. P.
 | last9=Hoffmann | first9=W. F. | last10=Mennesson | first10=B.
 | last11=Millan-Gabet | first11=R. | last12=Danchi | first12=W. C.
 | last13=Absil | first13=O. | last14=Arbo | first14=P.
 | last15=Beichman | first15=C. | last16=Bonavita | first16=M.
 | last17=Brusa | first17=G. | last18=Bryden | first18=G.
 | last19=Downey | first19=E. C. | last20=Esposito | first20=S.
 | last21=Grenz | first21=P. | last22=Haniff | first22=C.
 | last23=Hill | first23=J. M. | last24=Leisenring | first24=J. M.
 | last25=Males | first25=J. R. | last26=McMahon | first26=T. J.
 | last27=Montoya | first27=M. | last28=Morzinski | first28=K. M.
 | last29=Pinna | first29=E. | last30=Puglisi | first30=A.
 | last31=Rieke | first31=G. | last32=Roberge | first32=A.
 | last33=Rousseau | first33=H. | last34=Serabyn | first34=E.
 | last35=Spalding | first35=E. | last36=Skemer | first36=A. J.
 | last37=Stapelfeldt | first37=K. | last38=Su | first38=K.
 | last39=Vaz | first39=A. | last40=Weinberger | first40=A. J.
 | last41=Wyatt | first41=M. C. | display-authors=1
 | journal=The Astronomical Journal
 | volume=161 | issue=4 | id=186
 | date=April 2021 | page=186 | doi=10.3847/1538-3881/abe3ff 
 | arxiv=2103.03268 | bibcode=2021AJ....161..186D | s2cid=232135141 | doi-access=free }}
*{{cite journal | display-authors=1
 | title=Multiwavelength modelling of the β Leo debris disc: one, two or three planetesimal populations?
 | last1=Churcher | first1=L. J. | last2=Wyatt | first2=M. C.
 | last3=Duchêne | first3=G. | last4=Sibthorpe | first4=B.
 | last5=Kennedy | first5=G. | last6=Matthews | first6=B. C.
 | last7=Kalas | first7=P. | last8=Greaves | first8=J.
 | last9=Su | first9=K. | last10=Rieke | first10=G.
 | journal=Monthly Notices of the Royal Astronomical Society
 | volume=417 | issue=3 | pages=1715–1734
 | date=November 2011 | doi=10.1111/j.1365-2966.2011.19341.x 
 | doi-access=free
 | arxiv=1107.0316 | bibcode=2011MNRAS.417.1715C | s2cid=73557018
 }}
*{{cite journal 
 | title=The Structure of the β Leonis Debris Disk
 | last1=Stock | first1=Nathan D. | last2=Su | first2=Kate Y. L.
 | last3=Liu | first3=Wilson | last4=Hinz | first4=Phil M.
 | last5=Rieke | first5=George H. | last6=Marengo | first6=Massimo
 | last7=Stapelfeldt | first7=Karl R. | last8=Hines | first8=Dean C.
 | last9=Trilling | first9=David E. | display-authors=1
 | journal=The Astrophysical Journal
 | volume=724 | issue=2 | pages=1238–1255
 | date=December 2010 | doi=10.1088/0004-637X/724/2/1238 
 | arxiv=1010.0003 | bibcode=2010ApJ...724.1238S | s2cid=28349642 }}
*{{cite journal 
 | title=The delta Scuti Star beta Leonis
 | display-authors=1 | last1=Bartolini | first1=C.
 | last2=Dapergolas | first2=A. | last3=Piccioni | first3=A.
 | journal=Information Bulletin on Variable Stars
 | volume=2010 | page=1 | date=August 1981
 | bibcode=1981IBVS.2010....1B }}
{{Div col end}}

==External links==
* {{cite web | last=Kaler | first=Jim | url=http://stars.astro.illinois.edu/sow/denebola.html | title=Denebola | work=Stars | publisher=University of Illinois | access-date=2012-01-14 }}

{{Stars of Leo}}

{{DEFAULTSORT:Denebola}}
[[Category:Bayer objects|Leonis, Beta]]
[[Category:Delta Scuti variables]]
[[Category:Leo (constellation)]]
[[Category:A-type main-sequence stars]]
[[Category:Gliese and GJ objects|0448]]
[[Category:Bright Star Catalogue objects|4534]]
[[Category:Hipparcos objects|057632]]
[[Category:Henry Draper Catalogue objects|102647]]
[[Category:Durchmusterung objects|BD+15 2383]]
[[Category:Flamsteed objects|Leonis, 94]]
[[Category:Stars with proper names|Denebola]]
[[Category:Circumstellar disks]]
[[Category:Population I stars]]