eta Microscopii

{{Starbox observe

| epoch = J2000.0

| equinox = J2000.0 (ICRS)

| constell = Microscopium

| ra = {{RA|21|06|25.51950}}

| dec = {{DEC|−41|23|09.4805}}

| appmag_v = 5.53

}}

{{Starbox character

| class = K3 III

| b-v = +1.35

| u-b = +1.50

| variable =

}}

{{Starbox astrometry

| radial_v = {{Val|+22.29|0.13}}

| prop_mo_ra = +28.760

| prop_mo_dec = −11.548

| parallax = 3.5657

| p_error = 0.1149

| parallax_footnote =

| absmag_v = −1.13

}}

{{Starbox detail

| source =

| mass = 1.2

| radius = {{Val|47.41|0.95|5.67}}

| luminosity = {{Val|735|28}}

| temperature = {{Val|4365|287|43|fmt=commas}}

| gravity = 1.1

| metal_fe = −0.31

| rotational_velocity =

| age_myr =

}}

{{Starbox catalog

| names = {{odlist | B=η Mic | CD=−41°14379| FK5=3684 | HD=200702 | HIP=104177 | HR=8069 | SAO=230523 | GC=29461 }}

}}

{{Starbox reference

| Simbad = eta+Mic

}}

Eta Microscopii, Latinised as η Microscopii, is a solitary star in the constellation Microscopium. It is visible to the naked eye as a dim, orange-hued star with an apparent visual magnitude of 5.53. The star is located around 910 light-years distant from the Sun based on parallax, and is drifting further away with a radial velocity of +22 km/s.

This is an aging giant star with a stellar classification of K3 III, indicating that it has exhausted the supply of hydrogen at its core then cooled and expanded. At present it has around 47 times the girth of the Sun. The star is radiating 735 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,365 K.

Multiple star catalogues list two optical companions. Two arc-minutes away, the 8th magnitude HD 200733 is a main sequence star much closer to Earth than η Microscopii. A 14th-magnitude star one arc-minute from η Microscopii is a background object.

References

{{reflist|refs=

{{citation |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 |postscript=. |doi-access=free }}

{{citation

| 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 | postscript=. }}

{{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 | doi-access=free | bibcode=2008MNRAS.389..869E

| arxiv=0806.2878 | s2cid=14878976 | postscript=. }}

{{citation

| last1=Houk | first1=Nancy

| title=Michigan catalogue of two-dimensional spectral types for the HD stars

| volume=2 | publication-place=Ann Arbor

| publisher=Dept. of Astronomy, University of Michigan

| year=1978 | bibcode=1978mcts.book.....H | postscript=. }}

{{citation

| title=Photoelectric UBV photometry of late-type stars in two regions at high galactic latitude

| last1=Drilling | first1=J. S.

| journal=Astronomical Journal | postscript=.

| volume=78 | pages=44–46 | date=February 1973

| doi=10.1086/111370 | bibcode=1973AJ.....78...44D }}

{{cite simbad

| title=eta Mic | accessdate=2017-08-12 | postscript=. | mode=cs2 }}

{{citation |postscript=. |bibcode=2019A&A...628A..94A |title=Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18 |last1=Anders |first1=F. |last2=Khalatyan |first2=A. |last3=Chiappini |first3=C. |last4=Queiroz |first4=A. B. |last5=Santiago |first5=B. X. |last6=Jordi |first6=C. |last7=Girardi |first7=L. |last8=Brown |first8=A. G. A. |last9=Matijevič |first9=G. |last10=Monari |first10=G. |last11=Cantat-Gaudin |first11=T. |last12=Weiler |first12=M. |last13=Khan |first13=S. |last14=Miglio |first14=A. |last15=Carrillo |first15=I. |last16=Romero-Gómez |first16=M. |last17=Minchev |first17=I. |last18=De Jong |first18=R. S. |last19=Antoja |first19=T. |last20=Ramos |first20=P. |last21=Steinmetz |first21=M. |last22=Enke |first22=H. |journal=Astronomy and Astrophysics |volume=628 |pages=A94 |year=2019 |arxiv=1904.11302 |doi=10.1051/0004-6361/201935765 |s2cid = 131780028}}

}}

Category:K-type giants

Category:Microscopium

Microscopii, Eta

Category:Durchmusterung objects

200702

104177

8069