HD 192310

{{Starbox image

| image=

{{Location mark

|image=Capricornus constellation map.svg|alt=|float=center|width=280

|label=|position=right

|mark=Red circle.svg|mark_width=10|mark_link=HD 192310

|x=810|y=790

}}

|caption=Location of HD 192310 (circled)

}}

{{Starbox observe

| epoch=J2000

| ra={{RA|20|15|17.39138}}

| dec={{DEC|−27|01|58.7116}}

| appmag_v=5.73

| constell=Capricornus

}}

{{Starbox character

| class=K2+ V

| b-v=0.88

| u-b=0.64

| variable=Suspected

}}

{{Starbox astrometry

| radial_v={{val|-54.41|0.13}}

| prop_mo_ra=1242.763

| prop_mo_dec=−181.175

| pm_footnote=

| parallax=113.4872

| p_error=0.0516

| parallax_footnote=

| absmag_v=6.0

}}

{{Starbox detail

| mass=0.78 ± 0.04

| radius=0.79–0.85

| luminosity=0.385 ± 0.007

| temperature=5069 ± 49

| metal_fe=-0.01 ± 0.05

| rotation=47.7 ± 4.9 days

| rotational_velocity=<3

| gravity=4.38 ± 0.19

| age_gyr=7.5–8.9

}}

{{Starbox catalog

| names=5 G. Capricorni, CD-27°14659, GCTP 4804.00, Gl 785, HD 192310, HIP 99825, HR 7722, LHS 488, LTT 8009, NSV 12933, SAO 189065

}}

{{Starbox reference

| Simbad=HR+7722

| NSTED=HD-192310

| ARICNS=01647

}}

HD 192310 (also known as 5 G. Capricorni or Gliese 785) is a star in the southern constellation of Capricornus. It is located in the solar neighborhood at a distance of {{convert|28.7|ly|pc|lk=on|abbr=off}}, and is within the range of luminosity needed to be viewed from the Earth with the unaided eye. (According to the Bortle scale, it can be viewed from dark suburban skies.) HD 192310 is suspected of being a variable star, but this is unconfirmed.

Description

This is a K-type main sequence star with a stellar classification of K2+ V. HD 192310 has about 78% of the Sun's mass and, depending on the estimation method, 79% to 85% of the radius of the Sun. The effective temperature of the photosphere is about 5069 K, giving it the orange-hued glow of a K-type star. It is older than the Sun, with age estimates in the range 7.5–8.9 billion years. The proportion of elements other than hydrogen and helium, known as the metallicity, is similar to that of the Sun. It is spinning slowly, completing a rotation roughly every 48 days.

The space velocity components of this star are (U, V, W) = {{nowrap|(–69, –13, –14) km/s}}. It is following an orbit through the Milky Way galaxy that has an orbital eccentricity of 0.18 at a mean galactocentric distance of 8.1 kpc. The star will achieve perihelion in around 82,200 years when it comes within {{Convert|6.188|pc|ly|abbr=on|lk=off|order=flip}} of the Sun.

Planetary system

The system has a Neptune-mass planet "b", discovered in 2010. A second planet "c" was found in this system in 2011 by the HARPS GTO program, along with the now-doubtful HD 85512 b and the planets of 82 G. Eridani. The uncertainty in the mass of the second planet was much higher than for the first because of the lack of coverage around the full orbit. Both planets may be similar in composition to Neptune. They are orbiting along the inner and outer edges of the habitable zone for this star.

A study in 2023 updated the parameters of these two planets, and identified a number of additional radial velocity signals. While most of these signals were attributed to stellar activity, one was considered a planet candidate. If real, this third planet would be a super-Earth orbiting closer to the star than the two known planets.{{rp|31}} However, another 2023 study did not find this candidate signal and also attributed it to stellar activity.{{rp|10}}

{{OrbitboxPlanet begin

| table_ref =

}}

{{OrbitboxPlanet

| exoplanet = b

| mass_earth = {{val|16.1|0.7|p=≥}}

| period = {{val|74.25|0.04}}

| semimajor = {{val|0.32|0.01}}

| eccentricity = {{val|0.11|0.02}}

}}

{{OrbitboxPlanet

| exoplanet = c

| mass_earth = {{val|15.9|0.9|p=≥}}

| period = {{val|534.9|5.9|5.1}}

| semimajor = {{val|1.21|0.02}}

| eccentricity = {{val|0.06|0.05|0.04}}

}}

References

{{Reflist|refs=

{{citation|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}}

{{citation | last1=Mamajek | first1=Eric E. | last2=Hillenbrand | first2=Lynne A. | title=Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics | journal=The Astrophysical Journal | volume=687 | issue=2 | pages=1264–1293 |date=November 2008 | doi=10.1086/591785 | bibcode=2008ApJ...687.1264M |arxiv = 0807.1686 | s2cid=27151456 }}

{{citation | display-authors=1 | last1=Gray | first1=R. O. | last2=Corbally | first2=C. J. | last3=Garrison | first3=R. F. | last4=McFadden | first4=M. T. | last5=Bubar | first5=E. J. | last6=McGahee | first6=C. E. | last7=O'Donoghue | first7=A. A. | last8=Knox | first8=E. R. | title=Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample | journal=The Astronomical Journal | volume=132 | issue=1 | pages=161–170 |date=July 2006 | doi=10.1086/504637 | bibcode=2006AJ....132..161G |arxiv = astro-ph/0603770 | s2cid=119476992 }}

{{Cite journal | display-authors=1 | last1=Johnson | first1=H. L. | last2=Iriarte | first2=B. | last3=Mitchell | first3=R. I. | last4=Wisniewskj | first4=W. Z. | title=UBVRIJKL photometry of the bright stars | journal=Communications of the Lunar and Planetary Laboratory | volume=4 | issue=99 | date=1966 | bibcode=1966CoLPL...4...99J | pages=99 }}

{{citation | display-authors=1 | title=Nitrogen abundances in planet-harbouring stars | last1=Ecuvillon | first1=A. | last2=Israelian | first2=G. | last3=Santos | first3=N. C. | last4=Mayor | first4=M. | last5=García López | first5=R. J. | last6=Randich | first6=S. | journal=Astronomy and Astrophysics | volume=418 | pages=703–715 |date=May 2004 | doi=10.1051/0004-6361:20035717 | bibcode=2004A&A...418..703E | arxiv=astro-ph/0401396 | issue=2 | s2cid=55400558 }}

{{citation | display-authors=1 | last1=Pasinetti Fracassini | first1=L. E. | last2=Pastori | first2=L. | last3=Covino | first3=S. | last4=Pozzi | first4=A. | title=Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics | journal=Astronomy and Astrophysics | volume=367 | pages=521–524 |date=February 2001 | issue=2 | doi=10.1051/0004-6361:20000451 | bibcode=2001A&A...367..521P |arxiv = astro-ph/0012289 | s2cid=425754 }}

{{citation | title=Astrobiologically Interesting Stars Within 10 Parsecs of the Sun | last1=Porto de Mello | first1=Gustavo | last2=del Peloso | first2=Eduardo F. | journal=Astrobiology | volume=6 | issue=2 | pages=308–331 |date=April 2006 | pmid=16689649 | doi=10.1089/ast.2006.6.308 | bibcode=2006AsBio...6..308P | arxiv=astro-ph/0511180 | s2cid=119459291 }}

{{citation | title=The metal-rich nature of stars with planets | last1=Santos | first1=N. C. | last2=Israelian | first2=G. | last3=Mayor | first3=M. | journal=Astronomy and Astrophysics | volume=373 | pages=1019–1031 |date=July 2001 | doi=10.1051/0004-6361:20010648 | bibcode=2001A&A...373.1019S |arxiv=astro-ph/0105216 | issue=3 | s2cid=119347084 }}

{{cite journal |last1=Howard |first1=Andrew W. |last2=Johnson |first2=John Asher |display-authors=etal |date=March 2011 |title=The NASA-UC Eta-Earth Program: III. A Super-Earth orbiting HD 97658 and a Neptune-mass planet orbiting Gl 785 |journal=The Astrophysical Journal |volume=730 |issue=1 |pages=10 |doi=10.1088/0004-637X/730/1/10 |arxiv=1011.0414 |bibcode=2011ApJ...730...10H|s2cid=17943021 }}

{{citation | display-authors=1 | title=The HARPS search for Earth-like planets in the habitable zone | work=VizieR On-line Data Catalog: J/A+A/534/A58 | last1=Pepe | first1=F. | last2=Lovis | first2=C. | last3=Segransan | first3=D. | last4=Benz | first4=W. | last5=Bouchy | first5=F. | last6=Dumusque | first6=X. | last7=Mayor | first7=M. | last8=Queloz | first8=D. | last9=Santos | first9=N. C. | date=2011 | volume=534 | pages=A58 | doi=10.1051/0004-6361/201117055 | arxiv=1108.3447 | bibcode=2011yCat..35340058P | s2cid=15088852 }}

{{citation | first=Jean | last=Schneider | title=HD 192310 c | url=http://exoplanet.eu/planet.php?p1=HD+192310&p2=c | access-date=2011-10-29 | url-status=dead | archive-url=https://web.archive.org/web/20111108233925/http://exoplanet.eu/planet.php?p1=HD+192310&p2=c | encyclopedia=Extrasolar Planets Encyclopaedia | archive-date=2011-11-08 }}

{{citation

| title=The Colour of Stars

| date=December 21, 2004

| work=Australia Telescope, Outreach and Education

| publisher=Commonwealth Scientific and Industrial Research Organisation

| url=http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html

| access-date=2012-01-16

| archive-url=https://web.archive.org/web/20120318151427/http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html

| archive-date=March 18, 2012

| url-status=dead

}}

{{citation

| last1=Bailer-Jones | first1=C. A. L.

| title=Close encounters of the stellar kind

| journal=Astronomy & Astrophysics

| volume=575 | id=A35 | pages=13 | date=March 2015

| doi=10.1051/0004-6361/201425221 | bibcode=2015A&A...575A..35B

| arxiv=1412.3648 | s2cid=59039482

}}

{{cite journal |last1=Laliotis |first1=Katherine |last2=Burt |first2=Jennifer A. |display-authors=etal |date=April 2023 |title=Doppler Constraints on Planetary Companions to Nearby Sun-like Stars: An Archival Radial Velocity Survey of Southern Targets for Proposed NASA Direct Imaging Missions |journal=The Astronomical Journal |volume=165 |issue=4 |pages=176 |doi=10.3847/1538-3881/acc067 |arxiv=2302.10310 |bibcode=2023AJ....165..176L |doi-access=free }}

{{cite journal |last1=Cretignier |first1=M. |last2=Dumusque |first2=X. |display-authors=etal |date=August 2023 |title=YARARA V2: Reaching sub-m s⁻¹ precision over a decade using PCA on line-by-line radial velocities |journal=Astronomy & Astrophysics |volume=678 |pages=A2 |doi=10.1051/0004-6361/202347232 |arxiv=2308.11812 |bibcode=2023A&A...678A...2C |s2cid=261076243 }}

}}