Groombridge 1830

{{Starbox_image

|image={{Location mark

| image = Ursa Major constellation map.svg

|width=300

|x%=41.4 |y%=83.4

|mark=Red circle.svg | mark_width=10

|float=center | mark_link=Groombridge 1830

}}

|caption=Groombridge 1830 (circled in red) in Ursa Major

}}

{{Starbox_image

|image=300px

|caption=Detailed position of HR 4550 ( = Groombridge 1830; bottom-left edge) related to χ UMa and ψ UMa

}}

{{Starbox observe

| epoch = J2000

| constell = Ursa Major

| ra = {{RA|11|52|58.76734}}

| dec = {{DEC|+37|43|07.2541}}

| appmag_v = 6.44

}}

{{Starbox character

| type = main sequence

| class = K1V Fe−1.5

| b-v = +0.75

| u-b = +0.16

| variable = Suspected

}}

{{Starbox astrometry

| radial_v = {{val|-98.05|0.12}}

| prop_mo_ra = +4,002.7

| prop_mo_dec = {{val|-5817.8|fmt=commas}}

| pm_footnote =

| parallax = 109.0296

| p_error = 0.0197

| parallax_footnote =

| absmag_v = 6.64

}}

{{Starbox detail

| source =

| mass = {{val|0.63|0.02}}

| radius = {{val|0.586|0.004}}

| luminosity = {{val|0.221|0.005}}

| temperature = {{val|5174|32|fmt=commas}}

| gravity = {{val|4.702|0.015}}

| metal_fe = {{val|-1.26|0.07}}

| rotation = 32.2

| rotational_velocity = 0.5

| age_gyr = 4.7–5.3

}}

{{Starbox catalog

| names = {{odlist | name=Groombridge 1830 | name2=Argelander's Star | V=CF UMa | BD=+38 2285 | FK5=1307 | GJ=451 | HD=103095 | HIP=57939 | HR=4550 | LHS=44 | LTT=13276 | PLX=2745 | SAO=62738 | Gmb=1830}}

}}

{{starbox reference

| Simbad = Groombridge+1830

}}

Groombridge 1830 is a star 29.9 light-years away in the constellation Ursa Major. With an apparent magnitude of 6.4, it is near the limit of naked eye visibility under ideal conditions. It has a low metallicity and is thought to be a superflare star.

Discovery and naming

The star was catalogued by British astronomer Stephen Groombridge with the Groombridge Transit Circle between 1806 and the 1830s and published posthumously in his star catalog, Catalogue of Circumpolar Stars (1838). The designation Groombridge 1830 comes from this catalog; in older sources it is sometimes written as 1830 Groombridge. Its high proper motion was noted by Friedrich Wilhelm Argelander in 1842, and so it is sometimes called Argelander's Star, a name first used in an 1853 paper.

Other designations for this star include HD 103095, HR 4550, and Gliese 451. It has the variable star designation CF Ursae Majoris, which originally referred to a supposed flaring companion star that is no longer believed to exist.

Description

Groombridge 1830 has been variously classified as a K-type main-sequence star, a G-type main-sequence star, or a G-type subdwarf. The low metallicity of this star makes some of its spectral lines resemble those of a G-class star, and it has been given as a spectral standard for the class G7V.

It is {{Convert|29.9|ly|pc|abbr=off|lk=on}} from the Sun as measured by the Gaia spacecraft, which, as the distance is nearly 10 parsecs, means its absolute magnitude is almost equal to its apparent magnitude. It is a member of the galactic halo; such stars account for only 0.1 to 0.2 percent of the stars near the Sun. Like most halo stars, it has a low abundance of elements other than hydrogen and helium—what astronomers term a metal-poor star.

Once suspected to be a binary star with a red dwarf flare star companion, the current consensus is that it is single. Previous observations of stellar flares, suspected to be from a companion star, were probably "superflares" on the primary star—analogous to the Sun's solar flares, but hundreds to millions of times more energetic. It was one of the first nine identified superflare stars.

Proper motion

When discovered, Groombridge 1830 had the highest known proper motion of any star, replacing 61 Cygni. Kapteyn's Star and Barnard's Star have since been identified as having even higher proper motions. It is considerably farther away than either of those stars, however, which means its transverse velocity is greater.{{cn|date=June 2025}}

References

{{reflist|refs=

{{cite web |title=CF UMa |url=https://vizier.cds.unistra.fr/viz-bin/VizieR-S?V*%20CF%20UMa |work=General Catalog of Variable Stars - VizieR |access-date=22 April 2025}}

{{cite journal |bibcode=2014MNRAS.444.3517M |title=A BCool magnetic snapshot survey of solar-type stars |last1=Marsden |first1=S. C. |last2=Petit |first2=P. |last3=Jeffers |first3=S. V. |last4=Morin |first4=J. |last5=Fares |first5=R. |last6=Reiners |first6=A. |last7=Do Nascimento |first7=J. -D. |last8=Aurière |first8=M. |last9=Bouvier |first9=J. |last10=Carter |first10=B. D. |last11=Catala |first11=C. |last12=Dintrans |first12=B. |last13=Donati |first13=J. -F. |last14=Gastine |first14=T. |last15=Jardine |first15=M. |last16=Konstantinova-Antova |first16=R. |last17=Lanoux |first17=J. |last18=Lignières |first18=F. |last19=Morgenthaler |first19=A. |last20=Ramìrez-Vèlez |first20=J. C. |last21=Théado |first21=S. |last22=Van Grootel |first22=V. |author23=BCool Collaboration |journal=Monthly Notices of the Royal Astronomical Society |date=2014 |volume=444 |issue=4 |page=3517 |doi=10.1093/mnras/stu1663 |doi-access=free |arxiv=1311.3374 }}

{{cite journal |language=de |bibcode=1842AN.....19..393A |title=Schreiben des Herrn Professors Argelander Directors der Sternwarte in Bonn, an den Herausgeber |last1=Argelander |first1=Friedrich Wilhelm August |journal=Astronomische Nachrichten |date=1842 |volume=19 |issue=26 |page=393 |doi=10.1002/asna.18420192604 }}

{{cite journal |last1=Peters |first1=C. A. F. |date=December 1853 |title=On the Parallax of Argelander's Star |journal=Monthly Notices of the Royal Astronomical Society |volume=14 |issue= 2|page=49 |doi=10.1093/mnras/14.2.49 |doi-access=free |bibcode=1853MNRAS..14...49P}}

{{cite journal |last1=Beardsley |first1=W. R. |last2=Gatewood |first2=G. |last3=Kamper |first3=K. W. |date=December 1974 |title=A study of an early flare, radial velocities, and parallax residuals for possible orbital motion of HD 103095 (Groombridge 1830). |journal=Astrophysical Journal |volume=194 |issue= |pages=637–643 |doi=10.1086/153284 |bibcode=1974ApJ...194..637B}}

{{cite journal |last1=Heintz |first1=W. D. |date=July 1984 |title=Astrometric study of the subdwarf HR 4550. |journal=Publications of the Astronomical Society of the Pacific |volume=96 |issue= |pages=557–558 |doi=10.1086/131379 |bibcode=1984PASP...96..557H}}

{{cite journal |bibcode=1986ApJ...309..260A |title=Spectral Classification of Weak-lined Stars Discovered Photometrically |last1=Abt |first1=Helmut A. |journal=The Astrophysical Journal |date=1986 |volume=309 |page=260 |doi=10.1086/164597 }}

{{cite journal |bibcode=2003AJ....126.2048G |title=Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 Parsecs: The Northern Sample. I. |last1=Gray |first1=R. O. |last2=Corbally |first2=C. J. |last3=Garrison |first3=R. F. |last4=McFadden |first4=M. T. |last5=Robinson |first5=P. E. |journal=The Astronomical Journal |date=2003 |volume=126 |issue=4 |page=2048 |doi=10.1086/378365 |arxiv=astro-ph/0308182 }}

{{cite journal |bibcode=1953ApJ...117..241K |title=Spectral Classification of the High-Velocity Stars |last1=Keenan |first1=Philip C. |last2=Keller |first2=Geoffrey |journal=The Astrophysical Journal |date=1953 |volume=117 |page=241 |doi=10.1086/145687 }}

{{cite journal

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| title=The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics

| volume=501 | issue=3 |date=July 2009 | pages=941–947

| journal=Astronomy and Astrophysics

| doi=10.1051/0004-6361/200811191 | bibcode=2009A&A...501..941H

| arxiv=0811.3982 | s2cid=118577511 }}

{{cite journal |author1=Mamajek, Eric E. |author2=Hillenbrand, 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 }}

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{{cite journal | title=UBV photometry of 550 F, G and K type stars | last=Argue | first=A. N. | journal=Monthly Notices of the Royal Astronomical Society | volume=133 | issue=4 | pages=475–493 | date=1966 | bibcode=1966MNRAS.133..475A | doi=10.1093/mnras/133.4.475| doi-access=free }}

{{cite journal | author=Kukarkin, B. V. | display-authors=etal | date=1981 | title=Catalogue of suspected variable stars | journal=Nachrichtenblatt der Vereinigung der Sternfreunde | publisher=Academy of Sciences | location=Moscow, USSR | bibcode=1981NVS...C......0K }}

{{cite web | url=http://www.solstation.com/stars/groo1830.htm | title=Groombridge 1830 | publisher=SolStation |archive-url=https://web.archive.org/web/20231206112153/http://www.solstation.com/stars/groo1830.htm |archive-date=6 December 2023 |url-status=dead}}

{{cite journal | title=Superflares and Giant Planets | last=Rubenstein | first=Eric P. | journal=American Scientist | volume=89 | issue=1 | page=38 |date=February 2001 | doi=10.1511/2001.1.38 | bibcode=2001AmSci..89...38R |arxiv = astro-ph/0101573 | s2cid=119439101 }}

}}

Groombridge 1830

Discovery and naming

Description

Proper motion

See also

References

Further reading