EQ Virginis

{{Starbox image

| image = 250px

| caption = A light curve for EQ Virginis, plotted from Kepler data

}}

{{Starbox observe

| epoch = J2000

| constell = Virgo

| ra = {{RA|13|34|43.2063}}

| dec = {{DEC|−08|20|31.3353}}

| appmag_v = 9.36

}}

{{Starbox character

| type =

| class = K5Ve

| b-v =

| u-b =

| variable = {{nowrap|UV Cet + BY Dra}}

}}

{{Starbox astrometry

| radial_v = −23.16{{±|0.16}}

| prop_mo_ra = {{val|−286.577|0.110}}

| prop_mo_dec = {{val|−91.866|0.083}}

| pm_footnote =

| parallax = 48.7322

| p_error = 0.0587

| parallax_footnote =

| absmag_v = 10.51

}}

{{Starbox detail

| mass = 0.68

| radius = {{val|0.62|0.02|0.04}}

| luminosity = 0.136{{±|0.001}}

| temperature = 4,224{{±|80}}

| metal_fe = −0.144

| gravity = 4.49

| rotation = 3.9{{±|0.1}} days

| rotational_velocity = 2.06

| age_myr = 30-50

}}

{{Starbox catalog

| names = {{odlist | V=EQ Vir | GJ=517 | PLX=3101 | BD=−07°3646 | HD=118100 | SAO=139419 | 1E=1332.1-0804 | HERZ=13903 | RBS=1287 | HIP=66252 | LTT=5253 | Ross=478 }}

}}

{{Starbox reference

| Simbad = EQ+Vir

| ARICNS = 01063

}}

EQ Virginis is a single variable star in the equatorial constellation of Virgo. It has a baseline visual apparent magnitude of 9.36, but is a flare star that undergoes sporadic bursts of brightening. The star is located at a distance of 67 light-years from the Sun based on parallax measurements, but is drifting closer with a radial velocity of −23 km/s. It is a member of the IC 2391 moving group of stars, which is between 30 and 50 million years old.

This is an orange-hued K-type main-sequence star with a stellar classification of K5Ve, where the 'e' suffix indicates emission lines in the spectrum. It is a young, rapidly rotating star with a mean magnetic field strength of {{val|2500|300|ul=G|fmt=commas}}. The star is classified as an eruptive variable of the UV Ceti type and a BY Draconis variable. It shows strong chromospheric activity with extensive star spots that, on average, cover ~24% of the surface. The star displays a strong X-ray emission.

References

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}}

Category:K-type main-sequence stars

Category:Flare stars

Category:BY Draconis variables

Category:Virgo (constellation)

Category:Durchmusterung objects

Category:Emission-line stars