{{Short description|Variable star in the northern constellation Boötes}} {{Starbox begin | name = HD 135530 }} {{Starbox image | image = [[Image:HD135530LightCurve.png|250px]] | caption = A [[light curve]] for HD 135530, plotted from data published by Burggraaff ''et al.'' (2018)<ref name="Burggraaff"/> }} {{Starbox observe | epoch = J2000 | constell = [[Boötes]]<ref name=xhip/> | ra = {{RA|15|14|10.31472}}<ref name=dr3/> | dec = {{DEC|+42|10|17.0573}}<ref name=dr3/> | appmag_v = 6.13{{snd}}6.15<ref name=gcvs/> }} {{Starbox character | type = [[asymptotic giant branch|AGB]]<ref name=eggen1992/> | class = M2IIIa<ref name=Hoffleit1991/> | r-i = | v-r = | b-v = +1.62<ref name="MERMILLIOD"/> | u-b = | variable = unclassified<ref name="VSX"/> }} {{Starbox astrometry | radial_v = {{val|-4.42|0.21}}<ref name="Famaey2005"/> | prop_mo_ra = 20.065<ref name=dr3/> | prop_mo_dec = −14.631<ref name=dr3/> | parallax = 3.1796 | p_error = 0.0484 | parallax_footnote = <ref name=dr3/> | absmag_v = −1.68<ref name=xhip/> }} {{Starbox detail | mass = 1.2<ref name=starhorse/> | radius = 79<ref name=dr2/> | luminosity = 1,204<ref name=dr2/> | temperature = 3,820<ref name=dr2/> | metal_fe = −0.17<ref name=starhorse/> | gravity = 0.56<ref name=starhorse/> | rotation = | age = }} {{Starbox catalog | names = NSV 20281, [[Durchmusterung|BD]]+42°2577, [[Henry Draper Catalogue|HD]] 135530, [[Hipparcos catalogue|HIP]] 74571, [[Bright Star Catalogue|HR]] 5677, [[Smithsonian Astrophysical Observatory Star Catalog|SAO]] 45445 }} {{Starbox reference | Simbad = HD+135530 }} {{Starbox end}}
'''HD 135530''' is a [[variable star]] in the northern [[constellation]] of [[Boötes]]. With an average [[apparent magnitude]] of 6.14,<ref name="VSX"/> it is very faintly visible to the [[naked eye]] under excellent observing conditions.
HD 135530 has [[stellar evolution|evolved]] into a [[red giant]] on the [[asymptotic giant branch]], meaning that it has exhausted its core helium and is fusing hydrogen and helium in shells outside the core.<ref name=eggen1992/> Its photosphere has expanded to {{solar radius|79|link=y}} at an [[effective temperature]] of {{val|fmt=cvommas|3820|ul=K}} and shows a spectrum classified as M2IIIa, with ''IIIa'' indicating a star slightly more luminous than a typical giant.
Although listed only as a suspected variable in the [[General Catalogue of Variable Stars]], observations by the [[MASCARA]] team have shown that its brightness is in fact variable, with a period of about 20 days.<ref name="Burggraaff"/>
==References== <references> <ref name=dr2>{{cite Gaia DR2|1392570925854463360}}</ref>
<ref name=dr3>{{cite Gaia DR3|1392570925854463360}}</ref>
<ref name="VSX">{{cite web |title=NSV 20281 |url=https://www.aavso.org/vsx/index.php?view=detail.top&oid=58716 |website=The International Variable Star Index |publisher=AAVSO |access-date=21 April 2025}}</ref>
<ref name=eggen1992>{{cite journal |bibcode=1992AJ....104..275E |title=Asymptotic Giant Branch Stars Near the Sun |last1=Eggen |first1=Olin J. |journal=The Astronomical Journal |date=1992 |volume=104 |page=275 |doi=10.1086/116239 }}</ref>
<ref name="Burggraaff">{{cite journal | last1=Burggraaff |first1=O. | last2=Talens |first2=G. J. J. | last3=Spronck |first3=J. | last4=Lesage |first4=A. L. | last5=Stuik | first5=R. | last6=Otten | first6=G. P. P. L. | last7=Van Eylen | first7=V. | last8=Pollacco | first8=D. | last9=Snellen | first9=I. A. G. | title=Studying bright variable stars with the Multi-site All-Sky CAmeRA (MASCARA) | journal=Astronomy and Astrophysics | date=September 2018 | volume=617 | page=A32 | doi=10.1051/0004-6361/201833142 |arxiv=1806.02247 | bibcode=2018A&A...617A..32B| doi-access=free }}</ref>
<ref name="Famaey2005">{{Cite journal | display-authors=1 | last1 = Famaey | first1 = B. | last2 = Jorissen | first2 = A. | last3 = Luri | first3 = X. | last4 = Mayor | first4 = M. | last5 = Udry | first5 = S. | last6 = Dejonghe | first6 = H. | last7 = Turon | first7 = C. | title = Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters | journal = Astronomy and Astrophysics | volume = 430 | pages = 165–186 | date = 2005 | doi = 10.1051/0004-6361:20041272 | bibcode = 2005A&A...430..165F |arxiv = astro-ph/0409579 | s2cid = 17804304 }}</ref>
<ref name="MERMILLIOD">{{cite journal | last1=Mermilliod | first1=J.-C. | title=Compilation of Eggen's UBV data, transformed to UBV (unpublished) | journal=Catalogue of Eggen's UBV Data. SIMBAD | date=1986 | bibcode=1986EgUBV........0M }}</ref>
<ref name=Hoffleit1991>{{cite book | last1=Hoffleit | first1=D. | last2=Warren Jr | first2=W. H. | title=Bright Star Catalogue | publisher=Astronomical Data Center, NSSDC/ADC | edition=5th Revised (Preliminary Version) | date=1991 | url=http://vizier.u-strasbg.fr/viz-bin/VizieR-3?-source=V/50/ | access-date=2015-08-17 }}</ref>
<ref name=starhorse>{{cite journal |bibcode=2019A&A...628A..94A |title=Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18 |last1=Anders |first1=F. |last2=Khalatyan |first2=A. |last3=Chiappini |first3=C. |last4=Queiroz |first4=A. B. |last5=Santiago |first5=B. X. |last6=Jordi |first6=C. |author6-link=Carme Jordi |last7=Girardi |first7=L. |last8=Brown |first8=A. G. A. |last9=Matijevič |first9=G. |last10=Monari |first10=G. |last11=Cantat-Gaudin |first11=T. |last12=Weiler |first12=M. |last13=Khan |first13=S. |last14=Miglio |first14=A. |last15=Carrillo |first15=I. |last16=Romero-Gómez |first16=M. |last17=Minchev |first17=I. |last18=De Jong |first18=R. S. |last19=Antoja |first19=T. |last20=Ramos |first20=P. |last21=Steinmetz |first21=M. |last22=Enke |first22=H. |journal=Astronomy and Astrophysics |year=2019 |volume=628 |pages=A94 |doi=10.1051/0004-6361/201935765 |arxiv=1904.11302 |s2cid=131780028 }}</ref>
<ref name=xhip>{{cite journal | bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015 | arxiv=1108.4971 | title=XHIP: An extended hipparcos compilation | journal=Astronomy Letters | volume=38 | issue=5 | pages=331 | year=2012 | last1=Anderson | first1=E. | last2=Francis | first2=Ch. | s2cid=119257644 }}</ref>
<ref name=gcvs>{{cite journal | display-authors=1 | 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. | title=General Catalogue of Variable Stars | version=5.1 | journal=[[Astronomy Reports]] | year=2017 | volume=61 | issue=1 | pages=80–88 | bibcode=2017ARep...61...80S | doi=10.1134/S1063772917010085 | s2cid=125853869 }}</ref> </references>
==External links== * [http://webviz.u-strasbg.fr/viz-bin/VizieR-S?HR%205677 HR 5677] * [http://aladin.u-strasbg.fr/AladinPreview?-c=15+14+10.3106%2B42+10+17.074&ident=NSV+20281&submit=Aladin+previewer Image HD 135530]
{{Stars of Boötes}}
[[Category:Boötes]] [[Category:Henry Draper Catalogue objects|135530]] [[Category:Hipparcos objects|074571]] [[Category:M-type giants]] [[Category:Bright Star Catalogue objects|5677]] [[Category:Suspected variables]] [[Category:Durchmusterung objects]] [[Category:Asymptotic-giant-branch stars]]