{{Short description|Binary star system in the constellation Hercules}} {{Starbox begin}} {{Starbox image | image = 250px | caption = A light curve for 106 Herculis, plotted from ''TESS'' data<ref name=MAST/> }} {{Starbox observe | epoch = J2000 | constell = Hercules | ra = {{RA|18|20|17.91482}}<ref name=GaiaDR2/> | dec = {{DEC|+21|57|40.6622}}<ref name=GaiaDR2/> | appmag_v = 4.96<ref name=Ducati2002/> }} {{Starbox character | type = AGB<ref name=guerrero2020/> | class = M0&nbsp;III<ref name=Wu2010/> | b-v = +1.58<ref name=EgUBV/> | u-b = +1.98<ref name=EgUBV/> | variable = suspected SR<ref name=gcvs/><ref name=percy/> }} {{Starbox astrometry | radial_v = {{Val|-35.20|0.29}}<ref name=Soubiran2008/> | prop_mo_ra = +18.105<ref name=GaiaDR2/> | prop_mo_dec = -59.631<ref name=GaiaDR2/> | parallax = 8.5067 | p_error = 0.1739 | parallax_footnote = <ref name=GaiaDR2/> | absmag_v = −0.664<ref name=Soubiran2008/> }} {{Starbox detail | source= | mass = | radius = {{Val|44.32|2.70|5.89}}<ref name=GaiaDR2/> | temperature = {{Val|3789|6|fmt=commas}}<ref name=Wu2010/> | luminosity = {{Val|414.1|9.7}}<ref name=GaiaDR2/> | gravity = {{Val|1.56|0.09}}<ref name=Wu2010/> | metal_fe = {{Val|0.00|0.03}}<ref name=Wu2010/> | rotational_velocity = {{Val|5.0|1.0}}<ref name=Zamanov2008/> | age_gyr = }} {{Starbox catalog | names = {{odlist | F=106 Her | BD=+21°3390 | HD=168720 | HIP=89861 | HR=6868 | SAO=85941 | NSV=24405 }}<ref name=SIMBAD/> }} {{Starbox reference | Simbad=106+Her }} {{Starbox end}}

'''106 Herculis''' is a variable star in the northern constellation Hercules. It is visible to the naked eye as a faint, red-hued point of light with a baseline apparent visual magnitude of 4.96.<ref name=Ducati2002/> Based on its parallax, it is estimated to lie {{Convert|383|ly|pc|abbr=off}} away from the Sun.<ref name=Wu2010/> The star is moving closer to the Earth with a heliocentric radial velocity of -35&nbsp;km/s.<ref name=Soubiran2008/>

Eggleton and Tokovinin (2008) listed this as a suspected binary star system consisting of two roughly equal components.<ref name=Eggleton2008/> It appears as an ageing red giant with a stellar classification of M0III. This is a suspected semiregular variable star with a very small amplitude and a period of 40&nbsp;days or more.<ref name=percy/> Having exhausted the supply of hydrogen at its core, it has expanded to 44 times the Sun's radius.<ref name=GaiaDR2/> It is radiating around 414 times the luminosity of the Sun<ref name=GaiaDR2/> from its enlarged photosphere at an effective temperature of about {{val|fmt=commas|3,789|ul=K}}.<ref name=Wu2010/>

==References== <references> <ref name=SIMBAD>{{cite simbad | title=106 Her | access-date=2019-06-17 }}</ref>

<ref name=GaiaDR2>{{Cite Gaia DR2|4529690183608965504}}</ref>

<ref name=MAST>{{cite web | title=MAST: Barbara A. Mikulski Archive for Space Telescopes | url=https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html | publisher=Space Telescope Science Institute | access-date=27 November 2023}}</ref>

<ref name=percy>{{cite journal|bibcode=1993PASP..105.1422P|doi=10.1086/133324|title=The photometric variability of K giants|journal=Publications of the Astronomical Society of the Pacific|volume=105|pages=1422|year=1993|last1=Percy|first1=John R.|doi-access=free}}</ref>

<ref name=gcvs>{{cite journal|bibcode=2009yCat....102025S|title=VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)|journal=VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S|volume=1|pages=B/GCVS|display-authors=etal|last1=Samus|first1=N. N.|last2=Durlevich|first2=O. V.|year=2009}}</ref>

<ref name=Ducati2002>{{cite journal | first1=Ducati | last1=J. R. | title=VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system | journal=CDS/ADC Collection of Electronic Catalogues | volume=2237 | year=2002 | bibcode=2002yCat.2237....0D }}</ref>

<ref name=EgUBV>{{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 | date=1986 | bibcode= 1986EgUBV........0M }}</ref>

<ref name=Soubiran2008>{{cite journal | last1=Soubiran | first1=C. | last2=Bienaymé | first2=O. | last3=Mishenina | first3=T. V. | last4=Kovtyukh | first4=V. V. | title=Vertical distribution of Galactic disk stars | journal=Astronomy & Astrophysics | volume=480 | pages=91–101 | year=2008 | issue=1 | bibcode=2008A&A...480...91S | arxiv=0712.1370 | doi=10.1051/0004-6361:20078788 | s2cid=16602121 }}</ref>

<ref name=Wu2010>{{cite journal | display-authors=1 | last1=Wu | first1=Yue | last2=Singh | first2=H. P. | last3=Prugniel | first3=P. | last4=Gupta | first4=R. | last5=Koleva | first5=M. | title=Coudé-feed stellar spectral library – atmospheric parameters | journal=Astronomy & Astrophysics | volume=525 | pages=A71 | year=2010 | bibcode=2011A&A...525A..71W | arxiv=1009.1491 | doi=10.1051/0004-6361/201015014 | s2cid=53480665 }}</ref>

<ref name=Eggleton2008>{{cite journal | last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A. | title=A catalogue of multiplicity among bright stellar systems | journal=Monthly Notices of the Royal Astronomical Society | volume=389 | issue=2 | pages=869–879 | date=September 2008 | doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | bibcode=2008MNRAS.389..869E | arxiv=0806.2878 | s2cid=14878976 }}</ref>

<ref name=Zamanov2008>{{cite journal | display-authors=1 | title=Rotational velocities of the giants in symbiotic stars - III. Evidence of fast rotation in S-type symbiotics | last1=Zamanov | first1=R. K. | last2=Bode | first2=M. F. | last3=Melo | first3=C. H. F. | last4=Stateva | first4=I. K. | last5=Bachev | first5=R. | last6=Gomboc | first6=A. | last7=Konstantinova-Antova | first7=R. | last8=Stoyanov | first8=K. A. | journal=Monthly Notices of the Royal Astronomical Society | volume=390 | issue=1 | pages=377–382 | date=October 2008 | doi=10.1111/j.1365-2966.2008.13751.x | doi-access=free | bibcode=2008MNRAS.390..377Z | arxiv=0807.3817 | s2cid=118697261 }}</ref>

<ref name=guerrero2020>{{cite journal |last1=Guerrero |first1=Martín A. |last2=Ortiz |first2=Roberto |title=The effect of pulsation on the near-ultraviolet spectrum of AGB stars |journal=Monthly Notices of the Royal Astronomical Society |date=2020 |volume=491 |issue=1 |page=680 |doi=10.1093/mnras/stz2966 |doi-access=free |bibcode=2020MNRAS.491..680G }}</ref>

</references>

{{Stars of Hercules}}

Category:M-type giants Category:Semiregular variable stars Category:Hercules (constellation) Category:Durchmusterung objects Herculis, 106 168720 089861 6868 Category:Suspected variables