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Xi1 Canis Majoris

{{short description|Star in the constellation Canis Major}}

{{For|other star systems with this Bayer designation|Xi Canis Majoris}}

{{DISPLAYTITLE:Xi1 Canis Majoris}}

{{Starbox begin

| name = ξ1 Canis Majoris

}}

{{Starbox image

| image=

{{Location mark

|image=Canis Major constellation map.svg|alt=|float=center|width=260

|label=|position=right

|mark=Red circle.svg|mark_width=10|mark_link=ξ1 Canis Majoris

|x=482|y=624

}}

|caption=Location of ξ1 Canis Majoris (circled)

}}

{{Starbox observe

| epoch = J2000.0

| constell = Canis Major

| ra = {{RA|06|31|51.36636}}

| dec = {{DEC|−23|25|06.3181}}

| appmag_v = 4.33 – 4.36

}}

{{Starbox character

| class = B1 III

| b-v = −0.24

| u-b = −0.98

| variable = β Cep

}}

{{Starbox astrometry

| radial_v = +26.9

| prop_mo_ra = −2.91

| prop_mo_dec = +6.22

| parallax = 2.36

| p_error = 0.20

| parallax_footnote =

| absmag_v = −3.86

}}

{{Starbox detail

| mass = {{val|14.2|0.4}}

| gravity = {{val|3.78|0.07}}

| rotational_velocity = 0

| radius = {{val|7.9|0.6}}

| luminosity = {{val|30,900|8,900|6,900|fmt=commas}}

| temperature = {{val|27,000|1,000|fmt=commas}}

| metal_fe = −0.18

| age_myr = {{val|11.1|0.7}}

}}

{{Starbox catalog

| names={{odlist | B=ξ1 CMa | F=4 Canis Majoris | CD=−23°3991 | FK5= | HD=46328 | HIP=31125 | HR=2387 | SAO=171895 | ADS=5176 | CCDM=06319-2325 | GC=8496 }}

}}

{{Starbox reference

|Simbad=ksi01+CMa

}}

{{Starbox end}}

Xi1 Canis Majoris, Latinized from ξ1 Canis Majoris, is a Beta Cephei variable star in the constellation Canis Major. It is approximately 1,400 light years from Earth.

ξ1 Canis Majoris is a blue-white B-type star. It has generally been assigned a luminosity class of III (giant) or IV (subgiant), for example B1III or B0.5IV. Comparison of its properties with model evolutionary tracks suggest that it is a main sequence star about three quarters of the way through its main sequence lifetime.

File:Xi1CMaLightCurve.png for Xi1 Canis Majoris, plotted from TESS data]]

The apparent magnitude varies from +4.33 to +4.36 with a period of 5.03 hours. Its pulsations cause its radius to vary by 1.0% to 1.5%. At the same time its effective temperature by about {{val|500|ul=K}} above and below its mean temperature.

ξ1 Canis Majoris has the longest known rotation period of any B class star, taking around 30 years to complete one revolution on its axis. This is thought to be due to magnetic braking; ξ1 Canis Majoris has the strongest magnetic field of any β Cephei star and would be expected to spin down completely in around four million years. It also has the strongest and hardest X-ray emission of any β Cephei star.

ξ1 Canis Majoris forms a naked eye pairing with ξ2 Canis Majoris a little less than a degree away. The Washington Double Star Catalog lists two 14th magnitude companions about {{val|27|ul="}} away. In addition, an unseen close companion is suspected due to some faint emission lines in the spectrum that are best explained by a Be star invisible against the brighter primary.

References

{{reflist|refs=

{{cite web

| title=MAST: Barbara A. Mikulski Archive for Space Telescopes

| url=https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html

| publisher=Space Telescope Science Institute |access-date=20 August 2022}}

{{cite journal

| title=Validation of the new Hipparcos reduction

| last1=van Leeuwen | first1=F.

| journal=Astronomy and Astrophysics

| volume=474 | issue=2 | pages=653–664 | date=2007

| arxiv=0708.1752 | bibcode=2007A&A...474..653V

| doi=10.1051/0004-6361:20078357 | s2cid=18759600 }}

{{cite journal

| title=XHIP: An extended hipparcos compilation

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

| journal=Astronomy Letters

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

| bibcode=2012AstL...38..331A | doi=10.1134/S1063773712050015

| arxiv=1108.4971 | s2cid=119257644 }}

{{cite conference

| last=Evans | first=D. S. | date=June 20–24, 1966

| editor1-last=Batten | editor1-first=Alan Henry

| editor2-last=Heard | editor2-first=John Frederick

| contribution=The Revision of the General Catalogue of Radial Velocities

| title=Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30

| journal=Determination of Radial Velocities and Their Applications | volume=30 | pages=57 | bibcode=1967IAUS...30...57E }}

{{cite journal | display-authors=1

| last1=Johnson | first1=H. L. | last2=Iriarte | first2=B.

| last3=Mitchell | first3=R. I. | last4=Wisniewskj | first4=W. Z.

| title=UBVRIJKL photometry of the bright stars

| journal=Communications of the Lunar and Planetary Laboratory

| volume=4 | issue=99 | pages=99 | year=1966

| bibcode=1966CoLPL...4...99J }}

{{cite journal| display-authors=1 | last1=Hubrig | first1=S. | last2=Briquet | first2=M. | last3=De Cat | first3=P. | last4=Schoeller | first4=M. | last5=Morel | first5=T. | last6=Ilyin | first6=I. | title=New magnetic field measurements of beta Cephei stars and Slowly Pulsating B stars | journal=Astronomische Nachrichten | volume=330 | issue=4 | page=317 |date=January 2009 | bibcode=2009AN....330..317H | arxiv=0902.1314 | doi=10.1002/asna.200811187 | s2cid=17497112 }}

{{cite web|url=https://www.aavso.org/vsx/index.php?view=detail.top&oid=5509|title=International Variable Star Index|access-date=2018-11-13}}

{{cite journal|bibcode=2017MNRAS.471.2286S|title=The pulsating magnetosphere of the extremely slowly rotating magnetic β Cep star ξ1 CMa|journal=Monthly Notices of the Royal Astronomical Society|volume=471|issue=2|pages=2286|last1=Shultz|first1=M.|last2=Wade|first2=G. A.|last3=Rivinius|first3=Th.|last4=Neiner|first4=C.|last5=Henrichs|first5=H.|last6=Marcolino|first6=W.|author7=MiMeS Collaboration|year=2017|doi=10.1093/mnras/stx1632|doi-access=free|arxiv=1706.08820}}

{{cite journal|bibcode=2018MNRAS.478L..39S|title=The pulsationally modulated radial crossover signature of the slowly rotating magnetic B-type star ξ1 CMa|journal=Monthly Notices of the Royal Astronomical Society|volume=478|issue=1|pages=L39|last1=Shultz|first1=M.|last2=Kochukhov|first2=O.|last3=Wade|first3=G. A.|last4=Rivinius|first4=Th|year=2018|arxiv=1804.07535|doi=10.1093/mnrasl/sly070|doi-access=free }}

{{cite journal|bibcode=2001AJ....122.3466M|title=The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog|journal=The Astronomical Journal|volume=122|issue=6|pages=3466|last1=Mason|first1=Brian D.|last2=Wycoff|first2=Gary L.|last3=Hartkopf|first3=William I.|last4=Douglass|first4=Geoffrey G.|last5=Worley|first5=Charles E.|year=2001|doi=10.1086/323920|doi-access=free}}

}}

{{Stars of Canis Major}}

{{DEFAULTSORT:Xi1 Canis Majoris}}

Canis Majoris, Xi1

Category:Beta Cephei variables

Category:B-type giants

Category:Canis Major

2387

046328

031125

Category:Durchmusterung objects

Category:Double stars

Canis Majoris, 04