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Uncommon star 30 EP

125 Tau

RA 84.9342° · Dec 25.8971° · star

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Score breakdown

· 6 badges
30 pts · Uncommon
Uncommon 34 pts → Rare
  • Naked-eye visible +8
  • Hot blue B-type star +6
  • Subgiant (leaving the main sequence) +5
  • Blue-white star +5
  • Star +3
  • On the zodiac +3
Total score 30

4 more points to reach Rare.

Badges

  • Star · +3
  • Naked-eye visible · +8
  • On the zodiac · +3
  • Hot blue B-type star · +6
  • Subgiant (leaving the main sequence) · +5
  • Blue-white star · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads B3IV — 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 a subgiant, caught in the act of leaving the main sequence as the hydrogen in its core runs out.

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 5.2 you can see it with your own eyes from a dark site, over in Taurus.
  • Northern sky. It rides the northern half of the sky — an easier target the further north you are.
  • Best time of year. It stands highest in the middle of the night around December — that's when to go looking.

Could we get there?

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

Getting there

  • Aboard Voyager 1. ≈ 7.5 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-0.407
bv
-0.15
constellation
Tau
dist ly
427.4653
luminosity
126.7068
mag
5.18
name
125 Tau
spect
B3IV

About 125 Tau

125 Tau is an uncommon star. It lies about 427.5 light-years from Earth, sits in the constellation Tau, shines at apparent magnitude 5.18 and has spectral type B3IV.

Its spectrum reads B3IV — 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 125 Tau in the constellation Tau. At apparent magnitude 5.18, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 125 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 125 Tau is an uncommon star

125 Tau scores 30 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 4 points would lift it into a rarer tier.

That score comes from 6 science badges — Star, Naked-eye visible, On the zodiac, Hot blue B-type star, Subgiant (leaving the main sequence) and Blue-white 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.