R Leporis

{{Short description|Star in the constellation Lepus}}

{{Starbox begin

| name = R Leporis}}

{{Starbox image

| image = 250px

| caption=Location of R Leporis in the constellation Lepus.

}}

{{Starbox observe

| epoch = J2000.0

| equinox = J2000.0 (ICRS)

| constell = Lepus

| ra = {{RA|04|59|36.3487}}{{cite simbad|title=R Leporis|access-date=November 19, 2009}}

| dec = {{DEC|−14|48|22.518}}

| appmag_v=5.5 to 11.7R Lep, database entry, [http://www.sai.msu.su/groups/cluster/gcvs/gcvs/iii/iii.dat The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars] {{Webarchive|url=https://web.archive.org/web/20170620004609/http://www.sai.msu.su/groups/cluster/gcvs/gcvs/iii/iii.dat |date=2017-06-20 }}, Sternberg Astronomical Institute, Moscow, Russia. Accessed on line November 19, 2009.

}}

{{Starbox character

| class = C7,6e(N6e)

| b-v = +5.74[http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=V/50/catalog&recno=1607 HR 1607], database entry, The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version), D. Hoffleit and W. H. Warren, Jr., CDS ID [http://vizier.u-strasbg.fr/viz-bin/Cat?V/50 V/50]. Accessed on line November 19, 2009.

| r-i = +1.47

| variable = Mira

}}

{{Starbox astrometry

| radial_v = 32.4 ± 2

| prop_mo_ra = 6.798

| prop_mo_dec = −1.263

| pm_footnote=

| parallax = 2.1914

| p_error = 0.0602

| parallax_footnote = {{cite DR3|2987082722815713792}}

| absmag_v=

}}

{{Starbox detail

|mass=1.00{{snd}}2.02

|radius= {{solar radius calculator|type=AD|14|0.471|decimals=-1}}{{snd}}{{solar radius calculator|type=AD|18|0.471|decimals=-1}}{{efn|name=radius}}

|luminosity=13,200

|temperature=2,290{{cite journal|bibcode=2016A&A...588A.124L|arxiv=1601.07017|title=Constraints on the H2O formation mechanism in the wind of carbon-rich AGB stars|journal=Astronomy & Astrophysics|volume=588|pages=A124|last1=Lombaert|first1=R.|last2=Decin|first2=L.|last3=Royer|first3=P.|last4=De Koter|first4=A.|last5=Cox|first5=N. L. J.|last6=González-Alfonso|first6=E.|last7=Neufeld|first7=D.|last8=De Ridder|first8=J.|last9=Agúndez|first9=M.|last10=Blommaert|first10=J. A. D. L.|last11=Khouri|first11=T.|last12=Groenewegen|first12=M. A. T.|last13=Kerschbaum|first13=F.|last14=Cernicharo|first14=J.|last15=Vandenbussche|first15=B.|last16=Waelkens|first16=C.|year=2016|doi=10.1051/0004-6361/201527049|s2cid=62787287}}

|metal_fe={{val|-0.409}}

|gravity={{val|-0.6}}

}}

{{Starbox catalog

| names = {{odlist | V=R Lep | AAVSO=0455-14 | BD=−15 915 | GC=6093 | HD=31996 | HIP=23203 | HR=1607 | IRC=-10080 | PPM=215123 | RAFGL=667 | SAO=150058 }}

}}

{{Starbox reference

| Simbad=R+Lep}}

{{Starbox end}}

R Leporis (R Lep), sometimes called Hind's Crimson Star, is a well-known variable star in the constellation Lepus, near its border with Eridanus.

It is a carbon star which appears distinctly red. It is named after famous British astronomer J. R. Hind, who observed it in 1845. Its apparent magnitude varies from +5.5 to +11.7 with a period of 418–441 days; recent measurements give a period of 427.07 days. There may be a secondary period of 40 years. Guandalini and Cristallo calculated the luminosity of Mira variables based on their periods. Using a period of 427.07 days, they calculated the bolometric luminosity to be {{solar luminosity|13,200}}.{{cite journal | bibcode=2013A&A...555A.120G |title=Luminosities of carbon-rich asymptotic giant branch stars in the Milky Way |author = Guandalini, R. |author2 = Cristallo, S. |journal = Astronomy & Astrophysics |volume = 555 | id = A120 | pages = 7 |date=2013|arxiv = 1305.4203 |doi = 10.1051/0004-6361/201321225 |s2cid=54918450 }}

R Leporis has often been reported as an intense smoky red color, although this is not pronounced when the star is near its maximum brightness. It is reddest when it is dimmest, which occurs every 14.5 months. During these periods it is a candidate for the most-visible reddest star, but this claim is questionable. The red coloration may be caused by carbon in the star's outer atmosphere filtering out the blue part of its visible light spectrum. The star's discoverer, Hind, reported that it appeared "like a drop of blood on a black field."{{cite book|author=Richard Hinckley Allen|title=Star-names and Their Meanings|url=https://archive.org/details/bub_gb_5xQuAAAAIAAJ|year=1899|publisher=G.E. Stechert|location=New York|page=[https://archive.org/details/bub_gb_5xQuAAAAIAAJ/page/n291 269]}}

File:R Leporis as imaged by ALMA.tif|R Leporis as imaged by ALMA{{cite web |title=ALMA achieves its highest resolution observations |url=https://www.eso.org/public/announcements/ann23019/ |website=www.eso.org |access-date=15 November 2023 |language=en}}

File:RLeporis.jpg|An image of the carbon star R Leporis as seen in binoculars. R Leporis is the red star right of centre. The bright star in the lower left corner is Mu Leporis.

File:RLepLightCurve.png|The light curve of R Leporis from AAVSO V band data