Pi2 Octantis

{{other stars by Bayer designation|Pi Octantis{{!}}π Octantis}}

{{Starbox begin

| name = π² Octantis

}}

{{Starbox image

| image ={{Location mark

| image=Octans IAU.svg | alt= | float=center | width=250

| label= | position=center

| mark=Red circle.svg | mark_width=4 | mark_link=Pi2 Octantis

| x%=34 | y%=65

}}

| caption = Location of π² Octantis (circled)

}}

{{Starbox observe

| epoch = J2000.0 (ICRS)

| constell = Octans

| ra = {{RA|15|04|46.9232}}

| dec = {{DEC|-83|02|17.920}}

| appmag_v = 5.64 ± 0.01

}}

{{Starbox character

| class = G8 Ib

| b-v = +1.3

| u-b = +1.15

}}

{{Starbox astrometry

| radial_v = −13.8 ± 0.3

| parallax = 2.0741

| p_error = 0.0429

| parallax_footnote =

| prop_mo_ra = −8.312

| prop_mo_dec = −17.597

| absmag_v = −3.19

}}

{{Starbox detail

| mass = 7 ± 1

| radius = {{val|69.02|1.61|1.53}}

| luminosity = 2,709

| temperature = 4,588

| gravity =

| metal_fe =

| rotational_velocity = 5.7 ± 1.8

| age_myr = 43 ± 3

}}

{{Starbox catalog

| names = {{odlist|B = π² Oct|Gould = 22 G. Octantis |HD = 131246|CPD = −82°636|GC = 20145|HIP = 73771|HR = 5545|SAO = 258714}}

}}

{{Starbox reference

| Simbad = pi.02+Oct

}}

Pi² Octantis, Latinized from π² Octantis, is a solitary star situated in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.64, allowing it to be faintly visible to the naked eye under ideal conditions. Located 1,570 light years away, the star is approaching the Sun with a heliocentric radial velocity of {{val|-13.8|ul=km/s}}.

This object is an ageing late G-type supergiant that has 7 times the mass of the Sun and 69.02 times the radius of the Sun. It radiates at {{val|2709|ul=solar luminosity|fmt=commas}} from its enlarged photosphere at an effective temperature of 4,588 K, giving it an orange-yellow glow. Despite its advanced state, Pi² Octantis is still a young star at an age of 43 million years. It spins modestly with a projected rotational velocity of {{val|5.7|ul=km/s}}.

References

{{reflist||refs=

{{cite journal |last1=Høg |first1=E. |last2=Fabricius |first2=C. |last3=Makarov |first3=V. V. |last4=Urban |first4=S. |last5=Corbin |first5=T. |last6=Wycoff |first6=G. |last7=Bastian |first7=U. |last8=Schwekendiek |first8=P. |last9=Wicenec |first9=A. |title=The Tycho-2 catalogue of the 2.5 million brightest stars |journal=Astronomy and Astrophysics |date=March 2000 |volume=355 |pages=L27–L30 |issn=0004-6361 |bibcode=2000A&A...355L..27H}}

{{cite book|last1=Houk |first1=N. |last2=Cowley |first2=A. P. |title=University of Michigan Catalogue of two-dimensional spectral types for the HD stars. Volume I. Declinations -90_ to -53_ƒ0. |date=1975 |bibcode=1975mcts.book.....H }}

{{cite journal |last1=Johnson |first1=H. L. |last2=Mitchell |first2=R. I. |last3=Iriarte |first3=B. |last4=Wisniewski |first4=W. Z. |title=UBVRIJKL Photometry of the Bright Stars |journal=Communications of the Lunar and Planetary Laboratory |date=1 January 1966 |volume=4 |pages=99–110 |bibcode=1966CoLPL...4...99J}}

{{cite journal |last1=Gontcharov |first1=G. A. |title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system |journal=Astronomy Letters |date=November 2006 |volume=32 |issue=11 |pages=759–771 |doi=10.1134/S1063773706110065 |issn=1063-7737 |bibcode=2006AstL...32..759G |arxiv=1606.08053|s2cid=119231169 }}

{{cite journal |last1=Tetzlaff |first1=N. |last2=Neuhäuser |first2=R. |last3=Hohle |first3=M. M. |title=A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun: Catalogue of young runaway stars |journal=Monthly Notices of the Royal Astronomical Society |date=1 January 2011 |volume=410 |issue=1 |pages=190–200 |doi=10.1111/j.1365-2966.2010.17434.x |issn=0035-8711 |bibcode=2011MNRAS.410..190T |arxiv=1007.4883 |doi-access=free}}

{{cite journal |last1=McDonald |first1=I. |last2=Zijlstra |first2=A. A. |last3=Boyer |first3=M. L. |title=Fundamental parameters and infrared excesses of Hipparcos stars: Parameters and IR excesses from Hipparcos |journal=Monthly Notices of the Royal Astronomical Society |date=21 November 2012 |volume=427 |issue=1 |pages=343–357 |doi=10.1111/j.1365-2966.2012.21873.x |issn=0035-8711 |bibcode=2012MNRAS.427..343M |arxiv=1208.2037 |doi-access=free}}

{{cite journal |last1=De Medeiros |first1=J. R. |last2=Udry |first2=S. |last3=Burki |first3=G. |last4=Mayor |first4=M. |title=A catalog of rotational and radial velocities for evolved stars: II. Ib supergiant stars |journal=Astronomy & Astrophysics |date=November 2002 |volume=395 |issue=1 |pages=97–98 |doi=10.1051/0004-6361:20021214 |issn=0004-6361 |bibcode=2002A&A...395...97D |doi-access=free}}

{{cite journal |last1=Anderson |first1=E. |last2=Francis |first2=Ch. |title=XHIP: An extended hipparcos compilation |journal=Astronomy Letters |date=May 2012 |volume=38 |issue=5 |pages=331–346 |doi=10.1134/S1063773712050015 |language=en |issn=1063-7737 |bibcode=2012AstL...38..331A |arxiv=1108.4971|s2cid=119257644 }}

{{citation | last1=Eggleton | first1=P. P. | last2=Tokovinin | first2=A. A. | title=A catalogue of multiplicity among bright stellar systems | journal=Monthly Notices of the Royal Astronomical Society | volume=389 | issue=2 | pages=869–879 | date=September 2008 | doi=10.1111/j.1365-2966.2008.13596.x | bibcode=2008MNRAS.389..869E | arxiv=0806.2878 | s2cid=14878976 |doi-access=free}}

}}

Category:Octans

Octantis, Pi2

Category:G-type supergiants

Octantis, 22

Category:Durchmusterung objects

131246

73771

5545