HR 7955

{{Starbox observe

| constell = Cepheus

| epoch = J2000

| ra = {{RA|20|45|21.12879}}

| dec = {{DEC|+57|34|47.0080}}

| appmag_v = 4.51

}}

{{Starbox character

| class = F8IV-V + F9IV-V

}}

{{Starbox astrometry

| radial_v = {{Val|-32.82|0.04}}

| prop_mo_ra = −62.32

| prop_mo_dec = −236.00

| parallax = 36.64

| p_error = 0.48

| parallax_footnote =

| absmag_v = 2.35

}}

{{Starbox orbit

| reference =

| period_unitless = {{Val|494.16|0.58|u=days}}

| axis = {{Val|0.065|0.001}}

| axis_unitless = {{Val|50.2|0.5|ul=Gm|p=≥}}

| eccentricity = {{Val|0.551|0.004}}

| inclination = {{Val|24.53|3.13}}

| periarg = {{Val|68.86|0.76}}

| node = {{Val|325.21|1.05}}

| periastron = B 1996.335 ± 0.0017

}}

{{Starbox detail

| source =

| component1 = HR 7955 A

| mass = {{Val|1.071|0.037}}

| age_gyr = 2.25

| temperature =

| component2 = HR 7955 B

| mass2 = {{Val|1.047|0.037}}

}}

{{Starbox catalog

| names = {{odlist | BD=+57°2240 | FK5=782 | GJ=9706 | HD=198084 | HIP=102431 | HR=7955 | SAO=32862 }}

}}

{{Starbox reference

| Simbad=HD+198084

}}

HR 7955 is a binary star system in the northern circumpolar constellation of Cepheus, near the constellation border with Cygnus. It has a yellow-white hue and is faintly visible to the naked eye with a combined apparent visual magnitude of 4.51. The system is located at a distance of 89 light-years (27.3 parsecs) from the Sun, based on parallax. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.243 arc seconds per annum, and is drifting closer to the Sun with a radial velocity of -33 km/s.

The double-lined nature of this spectroscopic binary system was not announced until 1972. It has an orbital period of {{Convert|494.16|days|years|2|disp=out|abbr=off}} and an eccentricity of 0.551. Both components appear to be slightly evolved stars that are leaving the main sequence and becoming subgiant stars, with stellar classifications of F8IV-V and F9IV-V. They each have slightly greater mass than the Sun: 107% and 105%, respectively. The system is about 2.25 billion years old.

References

{{reflist|refs=

{{cite simbad | title= HD 198084 | access-date=6 September 2012}}

{{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 }}

{{cite journal

| title=The Nature of Overluminous F Stars Observed in a Radial-Velocity Survey

| last1=Griffin | first1=R. F. | last2=Suchkov | first2=A. A.

| journal=The Astrophysical Journal Supplement Series

| volume=147 | issue=1 | pages=103–144 | date=July 2003

| doi=10.1086/367855 | bibcode=2003ApJS..147..103G | doi-access=free }}

{{cite journal

| last1=Lépine | first1=Sébastien | last2=Shara | first2=Michael M.

| title=A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)

| journal=The Astronomical Journal

| volume=129 | issue=3 | pages=1483–1522 | date=March 2005

| doi=10.1086/427854 | arxiv=astro-ph/0412070

| bibcode=2005AJ....129.1483L | s2cid=2603568 }}

{{citation

| title=Spectroscopic binary orbits from photoelectric radial velocities. Paper 148: HR 7955

| last1=Griffin | first1=R. F.

| journal=The Observatory

| volume=119 | pages=272–283 | date=October 1999

| bibcode=1999Obs...119..272G }}

{{cite journal

| title=Validation of the new Hipparcos reduction

| last=van Leeuwen | first=F.

| journal=Astronomy and Astrophysics

| volume=474 | issue=2 | pages=653–664 | date=2007

| arxiv=0708.1752 | bibcode=2007A&A...474..653V

| doi=10.1051/0004-6361:20078357 | s2cid=18759600 }}

{{cite journal

| last1=Farrington | first1=C. D. | last2=Ten Brummelaar | first2=T. A.

| last3=Mason | first3=B. D. | last4=Hartkopf | first4=W. I.

| last5=McAlister | first5=H. A. | last6=Raghavan | first6=D.

| last7=Turner | first7=N. H. | last8=Sturmann | first8=L.

| last9=Sturmann | first9=J. | last10=Ridgway | first10=S. T.

| title=Separated Fringe Packet Observations with the CHARA Array. I. Methods and New Orbits for χ Draconis, HD 184467, and HD 198084

| display-authors=1 | journal=The Astronomical Journal

| volume=139 | issue=6 | pages=2308 | year=2010

| bibcode=2010AJ....139.2308F | doi=10.1088/0004-6256/139/6/2308 | s2cid=122357261 | doi-access= }}

{{cite journal

| title=S_B⁹: The ninth catalogue of spectroscopic binary orbits

| display-authors=1 | last1=Pourbaix | first1=D.

| last2=Tokovinin | first2=A. A. | last3=Batten | first3=A. H.

| last4=Fekel | first4=F. C. | last5=Hartkopf | first5=W. I.

| last6=Levato | first6=H. | last7=Morrell | first7=N. I.

| last8=Torres | first8=G. | last9=Udry | first9=S.

| journal=Astronomy and Astrophysics

| volume=424 | issue=2 | pages=727–732 | year=2004

| doi=10.1051/0004-6361:20041213 | arxiv=astro-ph/0406573

| bibcode=2004A&A...424..727P| s2cid=119387088 }}

{{citation

| title=Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants

| last1=Luck | first1=R. Earle

| journal=The Astronomical Journal

| bibcode=2017AJ....153...21L | arxiv=1611.02897

| doi=10.3847/1538-3881/153/1/21 | s2cid=119511744 | postscript=. | doi-access=free }}

}}

Category:F-type main-sequence stars

Category:F-type subgiants

Category:Spectroscopic binaries

Category:Cepheus (constellation)

Category:Durchmusterung objects