109 Herculis
{{Short description|Star in the constellation Hercules}}
{{Starbox begin}}
{{Starbox observe
| epoch = J2000
| constell = Hercules
| dec = {{DEC|+21|46|11.1096}}
}}
{{Starbox character
| u-b =
| variable =
}}
{{Starbox astrometry
| radial_v = {{Val|−57.55|0.27}}
| prop_mo_ra = +195.971
| prop_mo_dec = {{val|-243.234}}
| parallax = 26.9636
| p_error = 0.1049
}}
{{Starbox detail
| mass = {{Val|1.05|0.18}}
| radius = {{Val|11.55|0.20|0.19}}
| temperature = {{Val|4569|60|fmt=commas}}
| luminosity = {{val|52.4|3}}
| gravity = 2.24
| metal_fe = −0.06
| age_gyr = {{Val|6.39|2.71}}
}}
{{Starbox catalog
| names = {{odlist | F=109 Her | BD=+21°3411 | FK5=690 | HD=169414 | HIP=90139 | HR=6895 | SAO=86003 | WDS=J18237+2146 }}
}}
{{Starbox reference
| Simbad=109+Her
}}
{{Starbox end}}
109 Herculis is a single star in the northern constellation of Hercules. It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 3.84. The star is located around {{convert|121|ly|pc|abbr=off}} distant, based on parallax. It is moving closer to the Earth with a heliocentric radial velocity of −58 km/s, and may come as close as {{Convert|24.85|pc|ly|0|disp=out|abbr=off}} away in around 328,000 years.
This is an aging giant star with a stellar classification of K2IIIab. It is a red clump giant, meaning it is on the horizontal branch and is generating energy through helium fusion at its core. The star is roughly six billion years old with slightly more mass than the Sun. With the supply of hydrogen at its core exhausted, it has expanded to nearly 12 times the Sun's radius. The star is radiating 52 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,569 K.
This star, together with 93 Her, 95 Her, and 102 Her, formed Cerberus, the obsolete constellation[http://www.ianridpath.com/startales/cerberus.html Ian Ridpath's Star Tales - Cerberus]
References
{{reflist|refs=
{{cite simbad | title=109 Her | access-date=2019-06-18 }}
| title=XHIP: An extended hipparcos compilation
| last1=Anderson | first1=E. | last2=Francis | first2=Ch.
| journal=Astronomy Letters | postscript=.
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| bibcode=2012AstL...38..331A | arxiv=1108.4971
| doi=10.1134/S1063773712050015 | s2cid=119257644 }}
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| title=A catalogue of multiplicity among bright stellar systems
| journal=Monthly Notices of the Royal Astronomical Society
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| doi=10.1111/j.1365-2966.2008.13596.x | doi-access=free | bibcode=2008MNRAS.389..869E
| arxiv=0806.2878 | s2cid=14878976 | postscript=. }}
| first1=Ducati | last1=J. R.
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| journal=CDS/ADC Collection of Electronic Catalogues
| volume=2237 | year=2002 | postscript=.
| bibcode=2002yCat.2237....0D }}
| title=Mg II chromospheric radiative loss rates in cool active and quiet stars
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| arxiv=astro-ph/0409683 | s2cid=12136256 }}
{{cite DR3|4529285391533766400}}
| title=The Perkins catalog of revised MK types for the cooler stars
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| journal=Astrophysical Journal Supplement Series
| volume=71 | pages=245 | year=1989 | postscript=.
| bibcode=1989ApJS...71..245K | doi=10.1086/191373 }}
| title=Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer
| last1=Baines | first1=Ellyn K. | last2=Armstrong | first2=J. Thomas | last3=Schmitt | first3=Henrique R. | last4=Zavala | first4=R. T. | last5=Benson | first5=James A. | last6=Hutter | first6=Donald J. | last7=Tycner | first7=Christopher | last8=Belle | first8=Gerard T. van
| display-authors=1 | journal=The Astronomical Journal
| volume=155 | at=30 | year=2018 | issue=1 | postscript=.
| arxiv=1712.08109 | bibcode=2018AJ....155...30B
| doi=10.3847/1538-3881/aa9d8b | s2cid=119427037 | doi-access=free }}
| last1=Massarotti | first1=Alessandro | last2=Latham | first2=David W.
| last3=Stefanik | first3=Robert P. | last4=Fogel | first4=Jeffrey
| title=Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity
| display-authors=1 | journal=The Astronomical Journal
| volume=135 | issue=1 | pages=209–231 |date=January 2008
| doi=10.1088/0004-6256/135/1/209
| bibcode=2008AJ....135..209M | postscript=. | doi-access=free }}
| display-authors=1 | last1=Puzeras | first1=E.
| last2=Tautvaišienė | first2=G. | last3=Cohen | first3=J. G.
| last4=Gray | first4=D. F. | last5=Adelman | first5=S. J.
| last6=Ilyin | first6=I. | last7=Chorniy | first7=Y.
| title=High-resolution spectroscopic study of red clump stars in the Galaxy: iron-group elements
| journal=Monthly Notices of the Royal Astronomical Society
| volume=408 | issue=2 | pages=1225–1232 | date=October 2010
| doi=10.1111/j.1365-2966.2010.17195.x | doi-access=free | arxiv=1006.3857
| bibcode=2010MNRAS.408.1225P | s2cid=44228180 | postscript=. }}
}}
{{Stars of Hercules}}
{{DEFAULTSORT:109 Herculis}}
Category:Horizontal-branch stars
Category:Hercules (constellation)