View source for Astronomy:8 Aquilae

{{Short description|Star in the constellation Aquila}}
{{Starbox begin}}
{{Starbox image
| image = [[Image:8AqlLightCurve.png|300px]]
| caption = A [[Astronomy:Photometric system#Photometric letters|blue band]] [[Astronomy:Light curve|light curve]] for 8 Aquilae, adapted from Machado ''et al.'' (2007)<ref name="Machado"/>
}}
{{Starbox observe
 | epoch       = J2000
 | ra          = {{RA|18|51|22.15821}}<ref name=dr3/>
 | dec         = {{DEC|-03|19|04.2851}}<ref name=dr3/>
 | appmag_v    = 6.08<ref name=scfs/>
 | constell    = [[Astronomy:Aquila (constellation)|Aquila]]
}}
{{Starbox character
 | class       = F0&nbsp;IV<ref name=abt1995/> or F2&nbsp;III<ref name=na15_5_397/>
 | b-v         = {{Val|+0.299|0.007}}<ref name=Anderson2012/>
 | u-b         = +0.06<ref name=mnassa24_120/>
 | variable    = [[Astronomy:Delta Scuti variable|δ Sct]]<ref name=na15_5_397/>
}}
{{Starbox astrometry
 | radial_v    = +11.8<ref name=scfs/>
 | prop_mo_ra  = +2.019<ref name=dr3/>
 | prop_mo_dec = −21.411<ref name=dr3/>
 | parallax    = 12.0549
 | p_error     = 0.0268
 | parallax_error = <ref name=dr3/>
 | absmag_v    = 1.27<ref name=na15_5_397/>
}}
{{Starbox detail
 | mass        = 1.60<ref name=David2015/>
 | radius      = 3.0<ref name=dr3/>
 | luminosity  = 18.89<ref name=Anderson2012/>
 | temperature = {{Val|7395|251|fmt=commas}}<ref name=David2015/>
 | metal_fe    = 0.14<ref name=na15_5_397/>
 | gravity     = {{Val|3.88|0.14}}<ref name=David2015/>
 | rotational_velocity = 105<ref name=aaa393_3_897/>
 | age_myr     = 959<ref name=David2015/>
}}
{{Starbox catalog
 | names={{odlist | F=8 Aql | V=V1729 Aql | BD=-03°4392 | FK5=3500 | HD=174589 | HIP=92524 | HR=7101 | SAO=142706 }}<ref name=SIMBAD/>
}}
{{Starbox reference
 | Simbad=8+Aql
}}
{{Starbox end}}

'''8 Aquilae''' is a [[Astronomy:Star|star]] in the [[Celestial equator|equatorial]] [[Astronomy:Constellation|constellation]] of [[Astronomy:Aquila (constellation)|Aquila]],<ref name=SIMBAD/> located 271&nbsp;[[Light year|light year]]s away from the Sun. ''8 Aquilae'' is the [[Astronomy:Flamsteed designation|Flamsteed designation]]. It can be viewed with the naked eye in good seeing conditions, appearing as a dim, yellow-white hued star with an [[Astronomy:Apparent visual magnitude|apparent visual magnitude]] of 6.08.<ref name=scfs/> The star is moving further from the Earth with a heliocentric [[Astronomy:Radial velocity|radial velocity]] of +12&nbsp;km/s.<ref name=scfs/>

Abt and Morrell (1995) found a [[Astronomy:Stellar classification|stellar classification]] of F0&nbsp;IV<ref name=abt1995/> for this star, suggesting it is an [[Astronomy:F-type star|F-type]] [[Astronomy:Subgiant|subgiant]]. In their 2010 study, Fox Machado et al. assigned a class of F2&nbsp;III,<ref name=na15_5_397/> which matches an [[Astronomy:Stellar evolution|evolved]] [[Astronomy:Giant star|giant star]].  Despite the spectral classifications, evolutionary models place the star towards the end of its [[Astronomy:Main sequence|main sequence]] life, with an age of about a billion years.<ref name=David2015/><ref name=dr3/>

8 Aquilae is a [[Astronomy:Delta Scuti variable|Delta Scuti variable]] with at least three overlapping pulsation frequencies, although the total amplitude of its brightness variations is only about 0.02 magnitudes.<ref name=na15_5_397/>  It has a relatively high rotation rate, showing a projected rotational velocity of 105&nbsp;km/s.<ref name=aaa393_3_897/> It has 1.6<ref name=David2015/> times the mass of the Sun and is radiating 19<ref name=Anderson2012/> times the Sun's luminosity from its [[Astronomy:Photosphere|photosphere]] at an [[Astronomy:Effective temperature|effective temperature]] of about 7,395&nbsp;K.<ref name=David2015/>

==References==
{{reflist|refs=

<ref name="Machado">{{cite journal
 | last1=Machado | first1=L. Fox | last2=Michel | first2=E.
 | last3=Hernandez | first3=F. Perez | last4=Pena | first4=J. H.
 | last5=Li | first5=M. A. | last6=Pau | first6=S. | last7=Fernandez | first7=A.
 | last8=Michel | first8=J. P. | last9=Michel | first9=R. | last10=Pani | first10=A.
 | title=Multisite Observations of δ Scuti Stars 7 Aql and 8 Aql (a New δ Scuti Variable): The Twelfth STEPHI Campaign in 2003
 | journal=The Astronomical Journal | date=August 2007 | volume=134 | issue=2 | pages=860–866
 | doi=10.1086/520062 | bibcode=2007AJ....134..860F | arxiv=0706.0576 | s2cid=15349358 }}</ref>

<ref name=SIMBAD>{{cite simbad | title=8 Aql | access-date=April 25, 2019 }}</ref>

<ref name=dr3>{{cite Gaia DR3|4258727053454106112}}</ref>

<ref name=scfs>{{citation
 | title=Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions
 | last1=Wielen | first1=R. | last2=Schwan | first2=H.
 | last3=Dettbarn | first3=C. | last4=Lenhardt | first4=H.
 | last5=Jahreiß | first5=H. | last6=Jährling | first6=R.
 | journal=Veroeffentlichungen des Astronomischen Rechen-Instituts Heidelberg | publisher=Astronomisches Rechen-Institut Heidelberg
 | display-authors=1 | issue=35 | year=1999
 | volume=35 | page=1 | bibcode=1999VeARI..35....1W | postscript=. }}</ref>

<ref name=aaa393_3_897>{{citation
 | display-authors=1 | last1=Royer | first1=F.
 | last2=Grenier | first2=S. | last3=Baylac | first3=M.-O.
 | last4=Gómez | first4=A. E. | last5=Zorec | first5=J.
 | title=Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i in the northern hemisphere
 | journal=Astronomy and Astrophysics
 | year=2002 | volume=393 | issue=3 | pages=897–911
 | bibcode=2002A&A...393..897R | arxiv=astro-ph/0205255
 | doi=10.1051/0004-6361:20020943 | s2cid=14070763 | postscript=. }}</ref>

<ref name=mnassa24_120>{{citation
 | last1=Cousins | first1=A. W. J.
 | title=Photometric Data for Stars in the Equatorial Zone (Eighth List)
 | journal=Monthly Notes of the Astronomical Society of Southern Africa
 | volume=24 | pages=120 | year=1965
 | bibcode=1965MNSSA..24..120C | postscript=. }}</ref>

<ref name=na15_5_397>{{citation
 | display-authors=1 | last1=Fox Machado | first1=L.
 | last2=Alvarez | first2=M. | last3=Michel | first3=R.
 | last4=Moya | first4=A. | last5=Peña | first5=J. H.
 | last6=Parrao | first6=L. | last7=Castro | first7=A.
 | title=Strömgren photometry and spectroscopy of the δ Scuti stars 7 Aql and 8 Aql
 | journal=New Astronomy
 | volume=15 | issue=5 | pages=397–402 | date=July 2010
 | doi=10.1016/j.newast.2009.11.006 | postscript=.
 | bibcode=2010NewA...15..397F | arxiv=0912.2808 | s2cid=119241648 }}</ref>

<ref name=David2015>{{citation
 | last1=David | first1=Trevor J. | last2=Hillenbrand | first2=Lynne A.
 | title=The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets
 | journal=The Astrophysical Journal
 | volume=804 | issue=2 | pages=146 | year=2015
 | bibcode=2015ApJ...804..146D | doi=10.1088/0004-637X/804/2/146
 | arxiv=1501.03154 | s2cid=33401607 | postscript=. }}</ref>

<ref name=abt1995>{{citation
 | last1=Abt | first1=Helmut A. | last2=Morrell | first2=Nidia I.
 | title=The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars
 | journal=Astrophysical Journal Supplement
 | volume=99 | pages=135 | year=1995 | postscript=.
 | doi=10.1086/192182 | bibcode=1995ApJS...99..135A | doi-access=free }}</ref>

<ref name=Anderson2012>{{citation
 | title=XHIP: An extended hipparcos compilation
 | last1=Anderson | first1=E. | last2=Francis | first2=Ch.
 | journal=Astronomy Letters | postscript=.
 | volume=38 | issue=5 | pages=331 | year=2012
 | bibcode=2012AstL...38..331A | arxiv=1108.4971
 | doi=10.1134/S1063773712050015 | s2cid=119257644 }}</ref>

}}

==External links==
* [http://webviz.u-strasbg.fr/viz-bin/VizieR-S?HR%207101 HR 7101]
* [http://aladin.u-strasbg.fr/AladinPreview?-c=18+51+22.1576-03+19+04.284&ident=*+++8+Aql&submit=Aladin+previewer Image 8 Aquilae]

{{Stars of Aquila}}

{{DEFAULTSORT:8 Aquilae}}
[[Category:F-type subgiants]]
[[Category:F-type giants]]
[[Category:Delta Scuti variables]]
[[Category:Aquila (constellation)]]
[[Category:Objects with variable star designations|Aquilae, V1729]]
[[Category:Durchmusterung objects|BD-03 4392]]
[[Category:Flamsteed objects|Aquilae, 08]]
[[Category:Henry Draper Catalogue objects|174589]]
[[Category:Hipparcos objects|092524]]
[[Category:Bright Star Catalogue objects|7101]]

{{Sourceattribution|8 Aquilae}}