66 Tauri

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

{{Starbox begin}}

{{Starbox observe

|epoch=J2000

|constell=Taurus

|ra={{RA|04|23|51.82553}}{{cite journal|title=Validation of the new Hipparcos reduction|url=http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL|author=van Leeuwen, F.|display-authors=etal|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}}

|dec={{DEC|+09|27|39.4939}}

|appmag_v=5.098{{cite journal|title=The Tycho-2 catalogue of the 2.5 million brightest stars|author=Høg, E.|display-authors=etal|date=2000|journal=Astronomy and Astrophysics|volume=355|pages=L27–L30|bibcode=2000A&A...355L..27H}} (5.8 / 5.9)

}}

{{Starbox character

|class=A3V + A4V{{cite journal|bibcode=1969PASP...81..643C|doi=10.1086/128831|title=MK Classification of 142 Visual Binaries|journal=Publications of the Astronomical Society of the Pacific|volume=81|page=643|year=1969|last1=Christy|first1=James W.|last2=Walker|first2=R. L. Jr.|issue=482|doi-access=free}}

|b-v=+0.07{{cite journal|author1=Mermilliod, J.-C.|title=Compilation of Eggen's UBV data, transformed to UBV (unpublished)|journal=Catalogue of Eggen's UBV Data|url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?1986EgUBV........0M&db_key=AST&nosetcookie=1|date=1986|bibcode= 1986EgUBV........0M}}

|u-b=+0.10

}}

{{Starbox astrometry

|radial_v={{val|-8.70|1}}{{cite journal|title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system|author=Gontcharov, G. A.|date=2006|journal=Astronomy Letters|volume=32|issue=11|pages=759–771|bibcode=2006AstL...32..759G|doi=10.1134/S1063773706110065|arxiv=1606.08053|s2cid=119231169}}

|prop_mo_ra=−20.32

|prop_mo_dec=−5.32

|parallax=8.24

|p_error=0.31

|parallax_footnote=

|absmag_v=−0.32{{cite journal

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

| title=XHIP: An extended hipparcos compilation

| journal=Astronomy Letters

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

| bibcode=2012AstL...38..331A | arxiv=1108.4971

| doi=10.1134/S1063773712050015 | s2cid=119257644 }}

}}

{{Starbox orbit

|reference={{cite web|url=http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6|title=Sixth Catalog of Orbits of Visual Binary Stars|publisher=United States Naval Observatory|access-date=13 August 2017|archive-date=1 August 2017|archive-url=https://web.archive.org/web/20170801102553/http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6}}

|period=54.77

|axis=0.188

|inclination=34.2

|node=239.8

|periastron=1937.24

|eccentricity=0.720

|periarg=332.0

}}

{{Starbox detail

|component1=66 Tau A

|mass=2.89{{cite journal|last1=Cvetkovic, Z.|last2=Ninkovic, S.|title=On the Component Masses of Visual Binaries|journal=Serbian Astronomical Journal|volume=180|issue=180|pages=71–80|date=2010|doi=10.2298/SAJ1080071C|bibcode=2010SerAJ.180...71C|doi-access=free}}Cvetkovic et al. gives two possible mass sums: {{solar mass|2.89 / 2.76}} or {{solar mass|2.88 / 2.77}}.

|rotational_velocity=81{{cite journal|bibcode=2007A&A...463..671R|doi=10.1051/0004-6361:20065224|arxiv=astro-ph/0610785|title=Rotational velocities of A-type stars|journal=Astronomy and Astrophysics|volume=463|issue=2|page=671|year=2007|last1=Royer|first1=F.|last2=Zorec|first2=J.|last3=Gómez|first3=A. E.|s2cid=18475298}}

|component2=66 Tau B

|mass2=2.76

}}

{{Starbox catalog

|names={{odlist|B=r Tau|BD=+09°570|HD=27820|HIP=20522|HR=1381|SAO=111791}}

}}

{{Starbox reference

|Simbad=66+Tau

}}

{{Starbox end}}

66 Tauri, also known as r Tauri, is a binary star in the constellation of Taurus. The combined apparent magnitude of the system is 5.098, with the magnitudes of the two components being 5.8 and 5.9, respectively. Parallax measurements by Hipparcos put 66 Tauri at some 400 light-years (121 parsecs) away.

This is a visual binary where the positions of the two stars are tracked over time, and used to calculate an orbit. The two stars orbit each other every 55 years. Their orbit is fairly eccentric, at 0.720, and the two stars are separated by {{val|0.188|ul="}} on average. Both stars are A-type main-sequence stars with similar masses.