{{Short description|Star in the constellation Boötes}} {{Starbox begin}} {{Starbox image | image = [[Image:HPBooLightCurve.png|250px]] | caption = The [[Photometric_system#Photometric_letters|visual band]] [[light curve]] of HP Boötes, plotted from data published by Gaidos ''et al.'' (2000)<ref name="Gaidos"/> }} {{Starbox observe | epoch=J2000 | constell=[[Boötes]]<ref name=xhip/> | ra={{RA|14|50|15.8110}}<ref name=dr3/> | dec={{DEC|+23|54|42.634}}<ref name=dr3/> | appmag_v=5.99<ref name=aaa474_2_653/> }} {{Starbox character | type=[[main sequence]]<ref name=dr3/> | class=F9 IV-V<ref name=gray2001/> | b-v=+0.576<ref name=aaa474_2_653/> | u-b=+0.01<ref name=simbad/> | variable=[[BY Draconis variable|BY Dra]]<ref name="Kazarovets2006"/> }} {{Starbox astrometry | radial_v=−1.5<ref name=rgcrv/> | prop_mo_ra=+144.396<ref name=dr3/> | prop_mo_dec=+31.661<ref name=dr3/> | parallax=54.9502 | p_error=0.0343 | parallax_footnote=<ref name=dr3/> | absmag_v=+4.56<ref name=xhip/> }} {{Starbox detail | mass=0.97<ref name=aaas141_491/> | radius=1.1<ref name=dr3/> | luminosity=1.2<ref name=dr3/> | temperature=5,780<ref name=aaas141_491/> | metal_fe=−0.20<ref name=aaas141_491/> | gravity=4.18<ref name=aaas141_491/> | rotation=8.1<ref name=bowler2023/> | rotational_velocity=6.8<ref name=bowler2023/> | age_gyr=4.7<ref name=aaa501_3_941/> or 0.5<ref name=apj692_1_729/> }} {{Starbox catalog | names=[[Variable star designation|HP]] Boötis, [[Gliese-Jahreiss catalogue|GJ]] 564, [[Bonner Durchmusterung|BD]]+24°2786, [[Henry Draper Catalogue|HD]] 130948, [[Fifth Fundamental Catalogue|FK5]] 3172, [[Hipparcos catalogue|HIP]] 72567, [[Harvard Revised catalogue|HR]] 5534, [[Smithsonian Astrophysical Observatory catalogue|SAO]] 83553<ref name=simbad/> }} {{Starbox reference | Simbad = HD+130948 }} {{Starbox end}}
'''HD 130948''' or '''HP Boötis''' is a [[variable star]] with 2 [[brown dwarf]]s in the constellation [[Boötes]]. With an [[apparent magnitude]] of 6.0, it is faintly visible to the [[naked eye]] under very good observing conditions. It has a [[stellar classification]] of G1V, which means it is a [[main sequence]] star with a mass and surface temperature that are similar to the [[Sun]].
The estimated age of HD 130948 is similar to the Sun at 4.7 billion years (Gyr) old, but it has a lower proportion of elements (63%) other than hydrogen or helium. However, a separate study in 2009 gave a much younger age of {{val|0.5|0.3|ul=Gyr}} and a higher [[metallicity]] that is very similar to the Sun.<ref name=apj692_1_729/> [[Stellar evolution|Evolutionary]] models suggest that it is just reaching the end of its [[main sequence]] life.<ref name=dr3/>
Eric J. Gaidos ''et al.'' observed the star in 1998 and 1999, and discovered that it is a [[variable star]].<ref name="Gaidos2000"/> It was given its [[variable star designation]], HP Boötis, in 2006.<ref name="Kazarovets2006"/>
In 2002, a pair of [[co-orbiting]] [[brown dwarf]]s were discovered in orbit around this star. They were found using an adaptive optics instrument on the [[Gemini Observatory|Gemini North]] 8m telescope in Hawaii.<ref name=apj567_2_L133/> The pair have a 10-year orbital period about the primary star, and their combined mass is 10.9% of the Sun's mass.<ref name=apj692_1_729/>
The [[Space velocity (astronomy)|space velocity]] components of this star through the [[Milky Way]] galaxy are {{nowrap|(U, V, W)}} = {{nowrap|(−14.0, 14.7, −0.1)}}.<ref name=aaas141_491/>
==References== <references> <ref name=dr3>{{cite Gaia DR3|1265976524286377856}}</ref>
<ref name="Gaidos">{{cite journal |last1=Gaidos |first1=E. J. |last2=Henry |first2=G. W. |last3=Henry |first3=S. M. |title=Spectroscopy and Photometry of Nearby Young Solar Analogs |journal=The Astronomical Journal |date=August 2000 |volume=120 |issue=2 |pages=1006–1013 |doi=10.1086/301488 |bibcode=2000AJ....120.1006G |s2cid=16930014 |doi-access=free }}</ref>
<ref name="Kazarovets2006">{{cite journal |last1=Kazarovets |first1=E. V. |last2=Samus |first2=N. N. |last3=Durlevich |first3=O. V. |last4=Kireeva |first4=N. N. |last5=Pastukhova |first5=E. N. |title=The 78th Name-List of Variable Stars |journal=Information Bulletin on Variable Stars |date=August 2006 |volume=5721 |pages=1–45 |bibcode=2006IBVS.5721....1K |url=https://ibvs.konkoly.hu/pub/ibvs/5701/5721.pdf |access-date=6 December 2024}}</ref>
<ref name="Gaidos2000">{{cite journal |last1=Gaidos |first1=E. J. |last2=Henry |first2=G. W. |last3=Henry |first3=S. M. |title=Spectroscopy and Photometry of Nearby Young Solar Analogs |journal=The Astronomical Journal |date=August 2000 |volume=120 |issue=2 |pages=1006–1013 |bibcode=2000AJ....120.1006G |doi=10.1086/301488 }}</ref>
<ref name=bowler2023>{{cite journal |bibcode=2023AJ....165..164B |title=Rotation Periods, Inclinations, and Obliquities of Cool Stars Hosting Directly Imaged Substellar Companions: Spin-Orbit Misalignments Are Common |last1=Bowler |first1=Brendan P. |last2=Tran |first2=Quang H. |last3=Zhang |first3=Zhoujian |last4=Morgan |first4=Marvin |last5=Ashok |first5=Katelyn B. |last6=Blunt |first6=Sarah |last7=Bryan |first7=Marta L. |last8=Evans |first8=Analis E. |last9=Franson |first9=Kyle |last10=Huber |first10=Daniel |last11=Nagpal |first11=Vighnesh |last12=Wu |first12=Ya-Lin |last13=Zhou |first13=Yifan |journal=The Astronomical Journal |date=2023 |volume=165 |issue=4 |page=164 |doi=10.3847/1538-3881/acbd34 |doi-access=free |arxiv=2301.04692 }}</ref>
<ref name=gray2001>{{cite journal |bibcode=2001AJ....121.2148G |title=The Physical Basis of Luminosity Classification in the Late A-, F-, and Early G-Type Stars. I. Precise Spectral Types for 372 Stars |last1=Gray |first1=R. O. |last2=Napier |first2=M. G. |last3=Winkler |first3=L. I. |journal=The Astronomical Journal |date=2001 |volume=121 |issue=4 |page=2148 |doi=10.1086/319956 }}</ref>
<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=rgcrv>{{cite conference | last=Evans | first=D. S. | date=June 20–24, 1966 |editor1=Batten, Alan Henry |editor2=Heard, John Frederick | title=The Revision of the General Catalogue of Radial Velocities | book-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=aaas141_491>{{cite journal |author1=Chen, Y. Q. |author2=Nissen, P. E. |author3=Zhao, G. |author4=Zhang, H. W. |author5=Benoni, T. | title=Chemical composition of 90 F and G disk dwarfs | journal=Astronomy and Astrophysics Supplement | volume=141 | pages=491–506 |date=February 2000 |issue=3 | doi=10.1051/aas:2000124 | bibcode=2000A&AS..141..491C |arxiv = astro-ph/9912342 |s2cid=16273589 }}</ref>
<ref name=simbad>{{cite web | title=V* HP Boo -- Variable of BY Dra type | work=SIMBAD | publisher=[[Centre de Données astronomiques de Strasbourg]] | url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HD+130948 | access-date=2010-10-03 }}</ref>
<ref name=aaa501_3_941>{{cite journal |author1=Holmberg, J. |author2=Nordstrom, B. |author3=Andersen, J. | title=The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics | journal=Astronomy and Astrophysics | volume=501 | issue=3 |date=July 2009 | pages=941–947 | doi=10.1051/0004-6361/200811191 | bibcode=2009A&A...501..941H|arxiv = 0811.3982 |s2cid=118577511 }}</ref>
<ref name=apj567_2_L133>{{cite journal |author1=Potter, Daniel |author2=Martín, Eduardo L. |author3=Cushing, Michael C. |author4=Baudoz, Pierre |author5=Brandner, Wolfgang |author6=Guyon, Olivier |author7=Neuhäuser, Ralph |title=Hokupa'a-Gemini Discovery of Two Ultracool Companions to the Young Star HD 130948 |journal=The Astrophysical Journal |volume=567 |issue=2 |pages=L133–L136 |date=March 2002 |doi=10.1086/339999 | bibcode=2002ApJ...567L.133P |arxiv=astro-ph/0201431 |s2cid=16249194 }}</ref>
<ref name=apj692_1_729>{{cite journal |title=Dynamical Mass of the Substellar Benchmark Binary HD 130948BC |author1=Dupuy, Trent J. |author2=Liu, Michael C. |author3=Ireland, Michael J. |journal=The Astrophysical Journal |volume=692 |issue=1 |pages=729–752 |date=February 2009 |doi=10.1088/0004-637X/692/1/729 |bibcode=2009ApJ...692..729D |arxiv=0807.2450 |s2cid=119237470 }}</ref>
<ref name=xhip>{{cite journal |bibcode=2012AstL...38..331A |title=XHIP: An extended hipparcos compilation |last1=Anderson |first1=E. |last2=Francis |first2=Ch. |journal=Astronomy Letters |date=2012 |volume=38 |issue=5 |page=331 |doi=10.1134/S1063773712050015 |arxiv=1108.4971 }}</ref> </references>
{{Stars of Boötes}}
[[Category:Boötes]] [[Category:BY Draconis variables]] [[Category:Henry Draper Catalogue objects|130948]] [[Category:Hipparcos objects|072567]] [[Category:F-type main-sequence stars]] [[Category:Objects with variable star designations|Bootis, HP]] [[Category:Gliese and GJ objects|0564]] [[Category:Durchmusterung objects]] [[Category:Bright Star Catalogue objects|5534]]