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Epic variable star 63 EP

HD 171012

RA 278.2921° · Dec -18.3684° · star

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Score breakdown

· 9 badges
63 pts · Epic
Epic 78 pts → Anomaly
  • Supergiant +18
  • Intrinsically luminous (Mv < −2) +10
  • Toward the galactic centre +8
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Variable star +5
  • Gently variable +4
  • On the zodiac +3
  • A named variable star +3
Total score 63

15 more points to reach Anomaly.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • Toward the galactic centre · +8
  • On the zodiac · +3
  • Hot blue B-type star · +6
  • Supergiant · +18
  • Intrinsically luminous (Mv < −2) · +10
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B0Ia/ab — 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 luminous supergiant — among the largest and rarest stars in the galaxy.
  • 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 6.8 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Sagittarius.
  • 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 June — that's when to go looking.

Could we get there?

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

Properties

absmag
-2.725
bv
0.46
constellation
Sgr
dist ly
2609.248
luminosity
1071.5193
mag
6.79
name
HD 171012
spect
B0Ia/ab
var amplitude
0.06
var designation
V4398
var max
6.768
var min
6.828

About HD 171012

HD 171012 is an epic variable star. It lies about 2,609.2 light-years from Earth, sits in the constellation Sgr, shines at apparent magnitude 6.79 and has spectral type B0Ia/ab.

Its spectrum reads B0Ia/ab — 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 HD 171012 in the constellation Sgr. At apparent magnitude 6.79, it is an easy target for binoculars.

Like any astronomical target, HD 171012 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 HD 171012 is an epic variable star

HD 171012 scores 63 points on Spacedle's rarity scale, which places it in the epic tier. Another 15 points would lift it into a rarer tier.

That score comes from 9 science badges — Variable star, Distant (over 1,000 light-years), Toward the galactic centre, On the zodiac, Hot blue B-type star, Supergiant, Intrinsically luminous (Mv < −2) and Gently variable — 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.