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Epic variable star 50 EP

Tau1Lup

RA 216.5343° · Dec -45.2214° · star

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Score breakdown

· 9 badges
50 pts · Epic
Epic 78 pts → Anomaly
  • Intrinsically luminous (Mv < −2) +10
  • Naked-eye visible +8
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Variable star +5
  • Subgiant (leaving the main sequence) +5
  • Blue-white star +5
  • A named variable star +3
  • Barely variable (under 0.05 mag) +2
Total score 50

28 more points to reach Anomaly.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • Naked-eye visible · +8
  • Hot blue B-type star · +6
  • Subgiant (leaving the main sequence) · +5
  • Blue-white star · +5
  • Intrinsically luminous (Mv < −2) · +10
  • Barely variable (under 0.05 mag) · +2
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B2IV — 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.
  • 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 4.6 you can see it with your own eyes from a dark site, over in Lupus.
  • Southern sky. It rides the southern half of the sky — an easier target the further south you are.
  • Best time of year. It stands highest in the middle of the night around April — that's when to go looking.

Could we get there?

  • Verdict. Impossible with our current technology — and the next millennium of it.

Properties

absmag
-3.062
bv
-0.147
constellation
Lup
dist ly
1090.8229
luminosity
1461.504
mag
4.56
name
Tau1Lup
spect
B2IV
var amplitude
0.04
var designation
Tau-1
var max
4.541
var min
4.581

About Tau1Lup

Tau1Lup is an epic variable star. It lies about 1,090.8 light-years from Earth, sits in the constellation Lup, shines at apparent magnitude 4.56 and has spectral type B2IV.

Its spectrum reads B2IV — 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 Tau1Lup in the constellation Lup. At apparent magnitude 4.56, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, Tau1Lup 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 Tau1Lup is an epic variable star

Tau1Lup scores 50 points on Spacedle's rarity scale, which places it in the epic tier. Another 28 points would lift it into a rarer tier.

That score comes from 9 science badges — Variable star, Distant (over 1,000 light-years), Naked-eye visible, Hot blue B-type star, Subgiant (leaving the main sequence), Blue-white star, Intrinsically luminous (Mv < −2) and Barely variable (under 0.05 mag) — 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.