upsilon Ophiuchi

{{short description|Multiple star in the constellation Ophiuchus}}

{{Starbox image

| image =

{{Location mark

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

|label=|position=right

|mark=Red circle.svg|mark_width=10|mark_link=Upsilon Ophiuchi

|x=757|y=557

}}

| caption = Location of υ Ophiuchi (circled)

}}

{{Starbox observe

| epoch = J2000

| constell = Ophiuchus

| ra = {{RA|16|27|48.17331}}

| dec = {{DEC|−08|22|18.4156}}

| appmag_v = 4.62

}}

{{Starbox character

| type =

| class = kA2hA5VmA5

| b-v = +0.16

| u-b = +0.06

| variable =

}}

{{Starbox astrometry

| radial_v = −30.60

| prop_mo_ra = −97.526

| prop_mo_dec = −33.97

| parallax = 25.0819

| p_error = 0.2300

| parallax_footnote =

| absmag_v = 1.75

}}

{{Starbox orbit

| reference =

| primary = Aa1

| name = Aa2

| period_unitless = {{Val|27.218|0.0005|u=days}}

| axis_unitless = ≥ {{Convert|8720000|km|AU|disp=out|lk=on}}

| eccentricity = {{Val|0.744|0.002}}

| periastron = {{Val|2438914.84|0.01|ul=JD|fmt=commas}}

| periarg = {{Val|333.7|0.7}}

| k1 = {{Val|34.9|0.3}}

| k2 = {{Val|41.1|0.3}}

}}

{{Starbox orbit

| reference =

| primary = Aa

| name = Ab

| period = {{Val|82.8|1.4}}

| axis = {{Val|0.79|0.03}}

| inclination = {{Val|31.2|5.7}}

| node = {{Val|86.8|6.9}}

| periastron = B {{Val|1994.1|1.0}}

| eccentricity = {{Val|0.45|0.03}}

| periarg = {{Val|177.9|7.4}}

}}

{{Starbox detail

| component1 = Aa1

| mass = 1.83

| radius = {{solar radius calculator|type=AD|0.37|0.0399|decimals=1}}{{efn|name=radius}}

| temperature = 8,364

| luminosity = 16.56

| rotational_velocity = 44

| gravity = 4.45

| metal_fe = +0.14

| age_myr = 50

| component2 = Aa2

| mass2 = 1.47

| radius2 = {{solar radius calculator|type=AD|0.33|0.0399|decimals=1}}{{efn|name=radius}}

| age_myr2 = 50

}}

{{Starbox detail|no_heading=y

| component1 = Ab1

| mass = 0.82

| radius = {{solar radius calculator|type=AD|0.20|0.0399|decimals=2}}{{efn|name=radius}}

| age_myr = 45

| component2 = Ab2

| mass2 = 0.70

| radius2 = {{solar radius calculator|type=AD|0.16|0.0399|decimals=2}}{{efn|name=radius}}

| age_myr2 = 45

}}

{{Starbox catalog

| names = {{odlist | name=Alkarab | B=υ Oph | F=3 Ophiuchi | BD=−08°4243 | FK5=3299 | HD=148367 | HIP=80628 | HR=6129 | SAO=141187 | GC=22134 | CCDM=J16278-0822AB | WDS=J16278-0822 }}

}}

{{Starbox reference

| Simbad = Upsilon+Ophiuchi

}}

Hierarchy of orbits

Upsilon Ophiuchi is a quadruple star system in the equatorial constellation of Ophiuchus. It has a white hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.62. The distance to this system is approximately 130 light years based on parallax. It is drifting closer with a radial velocity of −30.6 km/s.

The variable radial velocity of the brighter component was first observed by H. A. Abt in 1961. It is a double-lined spectroscopic binary system with an orbital period of 27.2 days and an eccentricity of 0.74. They have a combined magnitude of 4.71. Both components are similar stars with a combined stellar classification of kA2hA5VmA5, and one or both are Am stars. The fainter component has an 82.8 year orbit with the brighter pair at an eccentricity of 0.45, and is itself binary, making the system a quadruple. The system is a source for X-ray emission.

This system forms part of the Upsilon Ophiuchi cluster, a small group of six stars which share similar kinematics and are spread over about eight degrees. The two brightest stars, apart from Upsilon Ophiuchi itself, are sometimes listed as components B and C: B is HD 148300, and C is HD 144660. Both are 9th-magnitude K-class dwarfs.

Notelist

{{notelist|notes=

{{efn|name=radius|1=Calculated using angular diameters (0.37, 0.33, 0.20 and 0.16 milliarcseconds) and a distance of 39.9 parsecs via the equation R/{{Solar radius}} = (107.5{{*}}{{theta}}{{*}}d)/1000, where {{theta}} is the angular diameter and d is the distance.}}

}}

References

{{reflist|refs=

{{cite simbad | title=ups Oph | access-date=2019-10-21 | mode=cs2 | postscript=. }}

{{cite journal |bibcode=2001KFNT...17..409K |title=All-sky compiled catalogue of 2.5 million stars |last1=Kharchenko |first1=N. V. |journal=Kinematika I Fizika Nebesnykh Tel |date=2001 |volume=17 |issue=5 |page=409 }}

{{cite journal

| title=A study of the spectroscopic binary 3nu Ophiuchi (HD 148367)

| last=Gutmann | first=F.

| journal=Publications of the Dominion Astrophysical Observatory Victoria

| volume=12 | pages=391–399 | date=1965

| bibcode=1965PDAO...12..391G }}

{{Cite journal |last1=Waisberg |first1=Idel |last2=Klein |first2=Ygal |last3=Katz |first3=Boaz |date=2025-01-01 |title=Hidden Companions to Intermediate-mass Stars. Upgraded Multiplicity 3 → 4. XXIV. Discovery of a 0.70 M⊙, 0.06 au Companion to Upsilon Ophiuchi Ab (Plus Discovery of the υ Oph Mini-cluster) |journal=Research Notes of the American Astronomical Society |volume=9 |issue=1 |pages=1 |doi=10.3847/2515-5172/ada35c |doi-access=free |bibcode=2025RNAAS...9....1W |issn=2515-5172}}

{{cite journal

| last1=Anderson | first1=E. | last2=Francis | first2=Ch.

| title=XHIP: An extended hipparcos compilation

| journal=Astronomy Letters

| volume=38 | issue=5 | pages=331 | year=2012

| bibcode=2012AstL...38..331A | arxiv=1108.4971

| doi=10.1134/S1063773712050015

| s2cid=119257644 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=V/137D/XHIP&HIP=80628 Vizier catalog entry]

{{cite journal

| last1=Hoffleit | first1=D. | last2=Warren | first2=W. H.

| title=VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991)

| journal=VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H

| volume=5050 | year=1995 | bibcode=1995yCat.5050....0H }}

{{cite journal

| last1=Mallama | first1=A.

| title=Sloan Magnitudes for the Brightest Stars

| journal=The Journal of the American Association of Variable Star Observers

| volume=42 | pages=443 | year=2014

| issue=2

| bibcode=2014JAVSO..42..443M

}}[http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=J/other/JAVSO/42.443/ugriz&HD=148367 Vizier catalog entry]

{{cite journal

| last=Wilson | first=R. E. | year=1953

| title=General Catalogue of Stellar Radial Velocities

| journal=Carnegie Institute Washington D.C. Publication | publisher=Carnegie Institution for Science

| bibcode=1953GCRV..C......0W | isbn=9780598216885 | lccn=54001336 }}

{{cite web

| title=Sixth Catalog of Orbits of Visual Binary Stars

| work=United States Naval Observatory

| url=http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6

| access-date=24 May 2017

| archive-date=1 August 2017

| archive-url=https://web.archive.org/web/20170801102553/http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6

| url-status=dead

}}

{{cite journal

| 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 | arxiv=1501.03154

| doi=10.1088/0004-637X/804/2/146

| s2cid=33401607 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=J/ApJ/804/146/table5&HIP=80628 Vizier catalog entry]

{{citation

| last1=Schröder | first1=C. | last2=Schmitt | first2=J. H. M. M.

| title=X-ray emission from A-type stars

| journal=Astronomy and Astrophysics

| volume=475 | issue=2 | pages=677–684 | date=November 2007

| doi=10.1051/0004-6361:20077429 | bibcode=2007A&A...475..677S | doi-access=free }}

{{cite journal