epsilon Microscopii

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

{{Starbox begin

| name = ε Microscopii

}}

{{Starbox image

|image=

{{Location mark

|image=Microscopium constellation map.svg|alt=|float=center|width=240

|label=|position=right

|mark=Red circle.svg|mark_width=10|mark_link=Epsilon Microscopii

|x=400|y=380

}}

|caption=Location of ε Microscopii (circled)

}}

{{Starbox observe

| epoch = J2000

| constell = Microscopium

| ra = {{RA|21|17|56.28399}}{{cite journal | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | year=2007 | last1=Van Leeuwen | first1=F. | s2cid=18759600 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-S?HIP%20105140 Vizier catalog entry]

| dec = {{DEC|-32|10|21.1515}}

| appmag_v = 4.71{{cite XHIP|105140}}

}}

{{Starbox character

| class = A1V{{cite journal | bibcode=1995yCat.5050....0H | title=VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised Ed. (Hoffleit+, 1991) | journal=VizieR On-line Data Catalog: V/50. Originally Published in: 1964BS....C......0H | volume=5050 | last1=Hoffleit | first1=D. | last2=Warren | first2=W. H. | year=1995 }}

| b-v = +0.06{{cite journal | bibcode=2014JAVSO..42..443M | title=Sloan Magnitudes for the Brightest Stars | journal=The Journal of the American Association of Variable Star Observers | volume=42 | issue=2 | pages=443 | last1=Mallama | first1=A. | year=2014 }}[http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=J/other/JAVSO/42.443/ugriz&HD=202627 Vizier catalog entry]

| u-b = +0.02

}}

{{Starbox astrometry

| radial_v = +7.20{{Cite journal | doi=10.1134/S1063773706110065 | bibcode=2006AstL...32..759G| title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system| journal=Astronomy Letters| volume=32| issue=11| pages=759–771| year=2006| last1=Gontcharov| first1=G. A.|arxiv = 1606.08053 | s2cid=119231169}}

| prop_mo_ra = +54.36

| prop_mo_dec = −23.29

| parallax = 19.7054

| p_error = 0.5472

| parallax_footnote = {{cite DR2|6784024126773616128}}

| absmag_v = 0.97

}}

{{Starbox detail

| mass = 2.18{{cite journal | bibcode=1999A&A...352..555A | arxiv=astro-ph/9911002 | title=Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures | journal=Astronomy and Astrophysics | volume=352 | pages=555–562 | last1=Allende Prieto | first1=C. | last2=Lambert | first2=D. L. | year=1999 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=J/A%2bA/352/555/table1&Name=HIP105140 Vizier catalog entry]

| radius = 2.2

| temperature = 9,126{{cite journal | bibcode=2015ApJ...804..146D | doi=10.1088/0004-637X/804/2/146 | arxiv=1501.03154 | title=The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets | journal=The Astrophysical Journal | volume=804 | issue=2 | pages=146 | year=2015 | last1=David | first1=Trevor J. | last2=Hillenbrand | first2=Lynne A. | s2cid=33401607 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=J/ApJ/804/146/table5&HIP=105140 Vizier catalog entry]

| luminosity = 35.62

| rotational_velocity = 127

| gravity = 4.37

| metal_fe = −0.01{{cite journal | bibcode=2012AstL...38..771G | doi=10.1134/S1063773712120031 | arxiv=1606.08814 | title=Dependence of kinematics on the age of stars in the solar neighborhood | journal=Astronomy Letters | volume=38 | issue=12 | pages=771–782 | year=2012 | last1=Gontcharov | first1=G. A. | s2cid=118345778 }} [http://vizier.u-strasbg.fr/viz-bin/VizieR-4?-source=J/PAZh/38/860/thin&HIP=105140 Vizier catalog entry]

| age_myr=525

}}

{{Starbox catalog

| names = {{odlist | B=ε Mic | CD=-32° 16498 | CPD=−32° 6329 | FK5=801 | HD=202627 | HIP=105140 | HR=8135 | SAO=212874 | GC=29774 }}

}}

{{Starbox reference

| Simbad = Epsilon+Microscopii

}}

{{Starbox end}}

Epsilon Microscopii, Latinized from ε Microscopii, is a single,{{cite journal | 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 }} white-hued star in the southern constellationof Microscopium. It is faintly visible to the naked eye with an apparent visual magnitude of 4.71. The annual parallax shift of the star is 19.7054 mas as measured from Earth, which yields a distance estimate of around 166 light years. It is moving further from the Sun with a radial velocity of +7 km/s.

This star has a stellar classification of A1 V, indicating it is an A-type main-sequence star that is generating energy through hydrogen fusion at its core. The stellar spectrum displays an overabundance of silicon in the star's atmosphere,{{citation | last1=Renson | first1=P. | last2=Manfroid | first2=J. | title=Catalogue of Ap, HgMn and Am stars | journal=Astronomy and Astrophysics | postscript=. | volume=498 | issue=3 | pages=961–966 | date=May 2009 | doi=10.1051/0004-6361/200810788 | bibcode=2009A&A...498..961R | url=https://zenodo.org/record/890529 | doi-access=free }} but the abundance of iron is the same as in the Sun. The star has 2.2 times the mass of the Sun and 2.2 times the Sun's radius. It is around a half billion years old and is spinning rapidly with a projected rotational velocity of 127 km/s. Epsilon Microscopii is radiating about 36 times the Sun's luminosity from its photosphere at an effective temperature of 9,126 K.

Epsilon Microscopii was a latter designation of the star 4 Piscis Austrini.{{cite journal | last=Wagman | first=M. | title=Flamsteed's Missing Stars | journal=Journal for the History of Astronomy |issue=3| volume=18 | page=220 |date=August 1987 | bibcode=1987JHA....18..209W | doi=10.1177/002182868701800305| s2cid=118445625 }}

This star was the brightest star in the obsolete constellation Globus Aerostaticus.[http://www.ianridpath.com/startales/globusaerostaticus.htm Ian Ridpath's Star Tales - Globus Aerostaticus]