W Mensae

{{Short description|Variable star in the constellation Mensa}}

{{Starbox begin

| name = W Mensae

}}

{{Starbox image

| image = 250px

| caption = A near-infrared (I band) light curve for W Mensae, plotted from OGLE data

}}

{{Starbox observe

| epoch = J2000.0

| equinox = J2000.0

| constell = Mensa

| pronounce =

| ra = {{RA|05|26|24.516}}{{cite journal |bibcode=2003yCat.2246....0C |title=VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) |journal=CDS/ADC Collection of Electronic Catalogues |pages=II/246 |volume=2246 |last1=Cutri |first1=Roc M. |last2=Skrutskie |first2=Michael F. |last3=Van Dyk |first3=Schuyler D. |last4=Beichman |first4=Charles A. |last5=Carpenter |first5=John M. |last6=Chester |first6=Thomas |last7=Cambresy |first7=Laurent |last8=Evans |first8=Tracey E. |last9=Fowler |first9=John W. |last10=Gizis |first10=John E. |last11=Howard |first11=Elizabeth V. |last12=Huchra |first12=John P. |last13=Jarrett |first13=Thomas H. |last14=Kopan |first14=Eugene L. |last15=Kirkpatrick |first15=J. Davy |last16=Light |first16=Robert M. |last17=Marsh |first17=Kenneth A. |last18=McCallon |first18=Howard L. |last19=Schneider |first19=Stephen E. |last20=Stiening |first20=Rae |last21=Sykes |first21=Matthew J. |last22=Weinberg |first22=Martin D. |last23=Wheaton |first23=William A. |last24=Wheelock |first24=Sherry L. |last25=Zacarias |first25=N. |year=2003 |url=http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=II/246 }}

| dec = {{DEC|-71|11|11.79}}

| appmag_v = 13.90 {{nowrap|(13.4_pg - <18.3_pg)}}

}}

{{Starbox character

| class = F5Ipec{{cite journal|bibcode=1990Ap&SS.172..263M|title=Identification charts for southern R Coronae Borealis-stars|journal=Astrophysics and Space Science|volume=172|pages=263–271|last1=Milone|first1=Luis A.|year=1990|issue=2|doi= 10.1007/BF00643318|s2cid=118353230}}

| appmag_2_passband = R

| appmag_2 = 13.700

| appmag_3_passband = J

| appmag_3 = 13.032

| appmag_4_passband = H

| appmag_4 = 12.831

| appmag_5_passband = K

| appmag_5 = 12.296

| appmag_6_passband =L (3.4um)

| appmag_6 =9.998{{±|0.022}}{{citation|arxiv=1809.01743|year=2020|title=A plethora of new R Coronae Borealis stars discovered from a dedicated spectroscopic follow-up survey|doi=10.1051/0004-6361/201834410|last1=Tisserand|first1=P.|last2=Clayton|first2=G. C.|last3=Bessell|first3=M. S.|last4=Welch|first4=D. L.|last5=Kamath|first5=D.|last6=Wood|first6=P. R.|last7=Wils|first7=P.|last8=Wyrzykowski|first8=Ł.|last9=Mróz|first9=P.|last10=Udalski|first10=A.|journal=Astronomy & Astrophysics|volume=635|pages=A14|bibcode=2020A&A...635A..14T|s2cid=119547939}}

| appmag_7_passband =M (4.6um)

| appmag_7 =9.138{{±|0.020}}

| appmag_8_passband =Q (22um)

| appmag_8 =7.577{{±|0.078}}

| r-i =

| v-r =

| b-v = +0.45

| u-b = −0.24

| j-h = 0.201

| j-k = 0.736

| variable = R CrB{{cite journal|bibcode=2009AcA....59..335S|arxiv=0912.2097|title=The Optical Gravitational Lensing Experiment. The OGLE-III Catalog of Variable Stars. V. R Coronae Borealis Stars in the Large Magellanic Cloud|journal=Acta Astronomica|volume=59|pages=335|last1=Soszyński|first1=I.|last2=Udalski|first2=A.|last3=Szymański|first3=M. K.|last4=Kubiak|first4=M.|last5=Pietrzyński|first5=G.|last6=Wyrzykowski|first6=Ł.|last7=Szewczyk|first7=O.|last8=Ulaczyk|first8=K.|last9=Poleski|first9=R.|year=2009|issue=4}}

}}

{{Starbox astrometry

| radial_v = +260{{cite journal|bibcode=1967IAUS...30...57E|title=The Revision of the General Catalogue of Radial Velocities|journal=Determination of Radial Velocities and Their Applications|volume=30|pages=57|last1=Evans|first1=D. S.|year=1967}}

| prop_mo_ra =

| prop_mo_dec =

| parallax =

| p_error =

| parallax_footnote =

| dist_ly = ~168,000

| dist_pc = ~51,500

| absmag_v = −4.8{{cite journal|bibcode=1975IAUS...67..147S|title=Some Statistics of Southern R Coronae Borealis Variables (abstract)|journal=Variable Stars and Stellar Evolution; Proceedings of the Symposium|volume=67|pages=147|last1=Sherwood|first1=Vicki E.|year=1975|doi=10.1007/978-94-010-9934-9_18|doi-broken-date=1 November 2024 }}

}}

{{Starbox detail

| source =

| mass =

| radius = 61{{cite journal|last1=Goldsmith|first1=M. J.|last2=Evans|first2=A.|last3=Albinson|first3=J. S.|last4=Bode|first4=M. F.|date=1990|title=Effective temperatures of RCB stars|journal=Monthly Notices of the Royal Astronomical Society|volume=245|issue=1|pages=119–29|issn=0035-8711|bibcode=1990MNRAS.245..119G}}

| gravity = 0.5

| luminosity = 7,700

| luminosity_bolometric =

| luminosity_visual =

| temperature = 6,700{{cite journal|bibcode=1994MNRAS.268..544P|title=An Abundance Analysis of R-Coronae Stars in the Galaxy and the Large Magellanic Cloud|journal=Monthly Notices of the Royal Astronomical Society|volume=268|issue=2|pages=544|last1=Pollard|first1=K. R.|last2=Cottrell|first2=P. L.|last3=Lawson|first3=W. A.|year=1994|doi=10.1093/mnras/268.2.544|doi-access=free}}

| metal =

| rotation =

| rotational_velocity =

| age =

| age_gyr =

}}

{{Starbox catalog

| names = W Mensae, HV 966, RMC 102, 2MASS J05262451-7111117, AAVSO 0527-71, OGLE LMC-RCB-13

}}

{{Starbox reference

|Simbad=W+Mensae

}}

{{Starbox end}}

W Mensae (W Men) is an unusual yellow supergiant star in the Large Magellanic Cloud in the southern constellation Mensa. It is an R Coronae Borealis variable and periodically decreases in brightness by several magnitudes.

W Men is very distant, being located in the neighboring galaxy Large Magellanic Cloud, where it lies on the southern metal-deficient edge. Despite its high luminosity, the star has a maximum apparent brightness of +13.8^m, too dim to be visible in a small telescope. Its radius has been calculated to be 61 times that of the Sun.

The variability of W Men was discovered in 1927 by W. J. Luyten.{{cite journal |last=Luyten |first=W. J. |authorlink=Willem Jacob Luyten |date=1927 |title=A New Irregular Variable of the R Coronae Type |journal=Harvard College Observatory Bulletin |issue=846 |pages=31–33 |id=1927BHarO.846...33L |bibcode=1927BHarO.846...33L |volume=846 }} It belongs to the very rare R Coronae Borealis class of variables which are often called "inverse novae" since they experience occasional very large drops in brightness. At minimum brightness, W Men has a photographic (blue) magnitude less than +18.3, being undetectable on photographic plates at the time.{{cite journal|bibcode=1975IBVS..989....1M|title=A Note on V CrA and W Men|journal=Information Bulletin on Variable Stars|volume=989|pages=1|last1=Milone|first1=L. A.|year=1975}} The drop in brightness is less pronounced at longer wavelengths, and the overall luminosity of the star is thought to be largely unchanged. The variations are caused by condensation of dust which temporarily obscures the star. Short wavelengths of light are absorbed and re-emitted as infra-red. Many R CrB variables show small amplitude pulsations and W Mensae has a pulsation period of approximately 67 days.