← Back to dex
Rare variable star 36 EP

2Xi Tau

RA 51.7923° · Dec 9.7327° · star

Loading sky survey…
🌌 View in 3D star map
Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 8 badges
36 pts · Rare
Rare 50 pts → Epic
  • Naked-eye visible +8
  • Hot blue B-type star +6
  • Variable star +5
  • Blue-white star +5
  • Gently variable +4
  • On the zodiac +3
  • A named variable star +3
  • Main-sequence star +2
Total score 36

14 more points to reach Epic.

Badges

  • Variable star · +5
  • Naked-eye visible · +8
  • On the zodiac · +3
  • Hot blue B-type star · +6
  • Main-sequence star · +2
  • Blue-white star · +5
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B9Vn — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.
  • Where it is in life. It is on the main sequence, quietly fusing hydrogen in its core exactly as the Sun does.
  • It changes. This star does not hold still: its brightness rises and falls on a rhythm of hours, days or years, either pulsing in size or being eclipsed by a companion.

Sense of scale

  • In perspective. Far away by human standards, yet still a local address inside the Milky Way's spiral arms.

Find it in the sky

  • How to spot it. At magnitude 3.7 you can see it with your own eyes from a dark site, over in Taurus.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • Best time of year. It stands highest in the middle of the night around November — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Properties

absmag
-0.304
bv
-0.082
constellation
Tau
dist ly
209.0745
luminosity
115.2391
mag
3.73
name
2Xi Tau
spect
B9Vn
var amplitude
0.09
var designation
Xi
var max
3.722
var min
3.812

About 2Xi Tau

2Xi Tau is a rare variable star. It lies about 209.1 light-years from Earth, sits in the constellation Tau, shines at apparent magnitude 3.73 and has spectral type B9Vn.

Its spectrum reads B9Vn — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.

How to see it

Look for 2Xi Tau in the constellation Tau. At apparent magnitude 3.73, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 2Xi Tau is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.

Why 2Xi Tau is a rare variable star

2Xi Tau scores 36 points on Spacedle's rarity scale, which places it in the rare tier. Another 14 points would lift it into a rarer tier.

That score comes from 8 science badges — Variable star, Naked-eye visible, On the zodiac, Hot blue B-type star, Main-sequence star, Blue-white star, Gently variable and A named variable star — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.