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R Geminorum

{{short description|Star in the constellation of Gemini}}{{confuse|Rho Geminorum}}

{{Starbox begin}}

{{Starbox image

| image = 250px

| caption = The visual band light curve of R Geminorum, from AAVSO data

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{{Starbox observe

| epoch = J2000

| constell = Gemini

| ra = {{RA|07|07|21.271}}

| dec = {{DEC|+22|42|12.75}}

| appmag_v = 6.0 - 14.0

}}

{{Starbox character

| type = AGB

| class = S2,9e-S8,9e(Tc)

| variable = Mira

}}

{{Starbox astrometry

| radial_v = −45.2

| prop_mo_ra = −8.765

| prop_mo_dec = 0.665

| parallax = 1.1795

| p_error = 0.0960

| parallax_footnote =

| absmag_v =

}}

{{Starbox detail

| mass =

| temperature = 2,400

| luminosity = 5,500

| radius = 431

}}

{{Starbox catalogue

|names={{odlist|BD= +22 1577|HD= 53791|HR= 2671|HIP= 34356|SAO= 79070}}

}}

{{Starbox reference

| Simbad = R+Gem

}}

{{Starbox end}}

R Geminorum (R Gem) is a Mira variable and technetium star in the constellation Gemini. It is located approximately {{convert|850|pc|ly}} away.

R Geminorum pulsates with an average period of 369.9 days, varying by up to eight magnitudes at visual wavelengths. When at maximum light its apparent visual magnitude is usually between 6 and 7, while at minimum light it is typically near magnitude 14.

R Geminorum is one of the brightest known examples of an S-type star, a type that is similar to M-type star, but whose spectra shows zirconium oxide, yttrium oxide and technetium. These exotic elements are formed in the star's core. Technetium has a half-life of just 4.2 million years, so it must have been brought up from the core relatively recently. R Gem has an unusual amount of it, even for an S-type star.

References

{{reflist|refs=

{{cite journal |bibcode=2022A&A...667A..74A |title=Distance estimates for AGB stars from parallax measurements |last1=Andriantsaralaza |first1=M. |last2=Ramstedt |first2=S. |last3=Vlemmings |first3=W. H. T. |last4=De Beck |first4=E. |journal=Astronomy and Astrophysics |date=2022 |volume=667 |pages=A74 |doi=10.1051/0004-6361/202243670 |arxiv=2209.03906 }}

{{cite web |title=Download Data |url=https://www.aavso.org/data-download |website=aavso.org |publisher=AAVSO |access-date=1 October 2021}}

{{cite Gaia EDR3|3368235472332290176}}

{{cite web |url =http://simbad.u-strasbg.fr/simbad/sim-id?Ident=R+gem&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = R Geminorum|work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |accessdate = 20 January 2014}}

{{cite journal|last1=MacRobert|first1=Alan|title=Weird R Gem Climbs to Maximum|journal=Sky & Telescope|date=January 2015|volume=129|issue=1|page=51|bibcode=2015S&T...129a..51M}}

{{cite journal |doi=10.1051/0004-6361/200911730 |title=Circumstellar molecular line emission from S-type AGB stars: Mass-loss rates and SiO abundances |year=2009 |last1=Ramstedt |first1=S. |last2=Schöier |first2=F. L. |last3=Olofsson |first3=H. |journal=Astronomy & Astrophysics |volume=499 |issue=2 |pages=515–527 |arxiv=0903.1672 |bibcode=2009A&A...499..515R |s2cid=17942939 }}

{{cite journal|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}}

{{cite journal |bibcode=2006AstL...32..759G |title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system |last1=Gontcharov |first1=G. A. |journal=Astronomy Letters |year=2006 |volume=32 |issue=11 |pages=759–771 |doi=10.1134/S1063773706110065 |arxiv=1606.08053 |s2cid=119231169 }}

{{cite web|url=http://www.aavso.org/lcg/plot?auid=000-BBM-508&starname=R+GEM&lastdays=20000&start=&stop=2457071.22531&obscode=&obscode_symbol=2&obstotals=yes&calendar=calendar&forcetics=&grid=on&visual=on&uband=on&bband=on&v=on&pointsize=1&width=800&height=450&mag1=&mag2=&mean=&vmean=|archive-url=https://archive.today/20150217180834/http://www.aavso.org/lcg/plot?auid=000-BBM-508&starname=R+GEM&lastdays=20000&start=&stop=2457071.22531&obscode=&obscode_symbol=2&obstotals=yes&calendar=calendar&forcetics=&grid=on&visual=on&uband=on&bband=on&v=on&pointsize=1&width=800&height=450&mag1=&mag2=&mean=&vmean=|url-status=dead|archive-date=February 17, 2015|title=Light Curve Generator|publisher=American Association of Variable Star Observers|accessdate=17 February 2015}}

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{{Stars of Gemini}}

{{DEFAULTSORT:R Geminorum}}

Category:Gemini (constellation)

Category:S-type stars

Category:Mira variables

Geminorum, R

Category:Durchmusterung objects

053791

2671

034356