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Uncommon star 27 EP

Eta1TrA

RA 250.3463° · Dec -68.2961° · star

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Score breakdown

· 5 badges
27 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
Total score 27

7 more points to reach Rare.

Badges

  • Star · +3
  • Naked-eye visible · +8
  • 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 B7IV — 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 5.9 you can see it with your own eyes from a dark site, over in Triangulum Australe.
  • Southern sky only. So far south it never rises for most of the northern hemisphere. To see it you'd have to travel to Chile, South Africa or Australia.
  • Best time of year. It stands highest in the middle of the night around May — 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. ≈ 11.6 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-0.646
bv
-0.078
constellation
TrA
dist ly
661.5742
luminosity
157.9065
mag
5.89
name
Eta1TrA
spect
B7IV

About Eta1TrA

Eta1TrA is an uncommon star. It lies about 661.6 light-years from Earth, sits in the constellation TrA, shines at apparent magnitude 5.89 and has spectral type B7IV.

Its spectrum reads B7IV — 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 Eta1TrA in the constellation TrA. At apparent magnitude 5.89, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, Eta1TrA 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 Eta1TrA is an uncommon star

Eta1TrA scores 27 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 7 points would lift it into a rarer tier.

That score comes from 5 science badges — Star, Naked-eye visible, 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.