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Rare variable star 42 EP

HD 170159

RA 277.1528° · Dec -12.9974° · star

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Score breakdown

· 6 badges
42 pts · Rare
Rare 50 pts → Epic
  • Supergiant +18
  • Distant (over 1,000 light-years) +6
  • Hot blue B-type star +6
  • Variable star +5
  • Gently variable +4
  • A named variable star +3
Total score 42

8 more points to reach Epic.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • Hot blue B-type star · +6
  • Supergiant · +18
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B1Iab — 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 supergiant. Drop it where the Sun is and its surface would engulf the inner planets.
  • 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 8.3 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Scutum.
  • 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
-0.612
bv
0.57
constellation
Sct
dist ly
2013.3088
luminosity
153.0383
mag
8.34
name
HD 170159
spect
B1Iab
var amplitude
0.09
var designation
V493
var max
8.319
var min
8.409

About HD 170159

HD 170159 is a rare variable star. It lies about 2,013.3 light-years from Earth, sits in the constellation Sct, shines at apparent magnitude 8.34 and has spectral type B1Iab.

Its spectrum reads B1Iab — 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 170159 in the constellation Sct. At apparent magnitude 8.34, it is an easy target for binoculars.

Like any astronomical target, HD 170159 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 170159 is a rare variable star

HD 170159 scores 42 points on Spacedle's rarity scale, which places it in the rare tier. Another 8 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, Distant (over 1,000 light-years), Hot blue B-type star, Supergiant, 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.