Sextans Dwarf Spheroidal

{{Short description|Galaxy in the constellation Sextans}}

{{Infobox Galaxy

| name = Sextans Dwarf Spheroidal

| image = Enana-Sextans-B-Ugc-5373.jpg

| epoch = J2000

| type = dSph{{cite web

| title=NASA/IPAC Extragalactic Database

| work=Results for Sextans Dwarf

| url=http://nedwww.ipac.caltech.edu/

| accessdate=2006-11-29 }}

| ra = {{RA|10|13|02.9}}

| dec = {{DEC|-01|36|53}}

| dist_ly = 290 ± 30 kly (90 ± 10 kpc){{cite journal

| author=I. D. Karachentsev| author2=V. E. Karachentseva| author3=W. K. Hutchmeier| author4=D. I. Makarov

| title=A Catalog of Neighboring Galaxies

| journal=Astronomical Journal

| date=2004

| volume=127

| issue=4

| pages=2031–2068

| bibcode=2004AJ....127.2031K

| doi=10.1086/382905| doi-access=free

}}{{cite journal

| author=Karachentsev, I. D.| author2=Kashibadze, O. G.

| title=Masses of the local group and of the M81 group estimated from distortions in the local velocity field

| journal=Astrophysics

| date=2006

| volume=49

| issue=1

| pages=3–18

| bibcode=2006Ap.....49....3K

| doi=10.1007/s10511-006-0002-6 | s2cid=120973010

}}

| z = 224 ± 2 km/s

| appmag_v = 10.4

| size_v = 30.0{{prime}} × 12.0{{prime}}

| constellation name = Sextans

| notes = satellite galaxy of the Milky Way

| names = Sextans I, LEDA 88608

}}

The Sextans Dwarf Spheroidal is a dwarf spheroidal galaxy that was discovered in 1990 by Mike Irwin as the 8th satellite of the Milky Way,{{cite journal|author=M. J. Irwin|author2=P. S. Bunclark|author3=M. T. Bridgeland|author4=R. G. McMahon|title=A new satellite galaxy of the Milky Way in the constellation of Sextans|journal=Monthly Notices of the Royal Astronomical Society|date=1990|volume=244|pages=16–19|bibcode=1990MNRAS.244P..16I}} located in the constellation of Sextans. It is also an elliptical galaxy, and displays a redshift because it is receding from the Sun at 224 km/s (72 km/s from the Galaxy). The distance to the galaxy is 320,000 light-years and the diameter is 8,400 light-years along its major axis.{{cite web | author = Hartmut Frommert | title = Sextans Dwarf | url = http://spider.seds.org/spider/LG/sex_dw.html | publisher = SEDS | accessdate = 2015-03-21}}

Like other dwarf spheroidal galaxies, the Sextans Dwarf's population consists of old, metal-poor stars: one study found that the majority of stars have a metallicity between [Fe/H] = −3.2 and −1.4. An analysis of several stars found them to also be deficient in barium, except for one star.{{cite journal|doi=10.1093/mnras/stab3189|arxiv=2110.09402|title=The formation of the Milky Way halo and its dwarf satellites: A NLTE–1D abundance analysis. V. The Sextans galaxy|year=2022|last1=Mashonkina|first1=L.|last2=Pakhomov|first2=Yu V.|last3=Sitnova|first3=T.|last4=Jablonka|first4=P.|last5=Yakovleva|first5=S. A.|last6=Belyaev|first6=A. K.|journal=Monthly Notices of the Royal Astronomical Society|volume=509|issue=3|pages=3626–3642|doi-access=free }}