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Common variable star 16 EP

HD 149805

RA 249.2152° · Dec 7.1072° · star

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Score breakdown

· 4 badges
16 pts · Common
Common 22 pts → Uncommon
  • Hot blue B-type star +6
  • Variable star +5
  • A named variable star +3
  • Barely variable (under 0.05 mag) +2
Total score 16

6 more points to reach Uncommon.

Badges

  • Variable star · +5
  • Hot blue B-type star · +6
  • Barely variable (under 0.05 mag) · +2
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B9 — 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.
  • 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 7.3 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Hercules.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • 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. ≈ 15.4 million years at Voyager 1's speed (17 km/s).

Properties

absmag
0.149
bv
0.016
constellation
Her
dist ly
874.4128
luminosity
75.9277
mag
7.29
name
HD 149805
spect
B9
var amplitude
0.03
var designation
Y
var max
7.274
var min
7.304

About HD 149805

HD 149805 is a common variable star. It lies about 874.4 light-years from Earth, sits in the constellation Her, shines at apparent magnitude 7.29 and has spectral type B9.

Its spectrum reads B9 — 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 149805 in the constellation Her. At apparent magnitude 7.29, it is an easy target for binoculars.

Like any astronomical target, HD 149805 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 149805 is a common variable star

HD 149805 scores 16 points on Spacedle's rarity scale, which places it in the common tier. Another 6 points would lift it into a rarer tier.

That score comes from 4 science badges — Variable star, Hot blue B-type star, Barely variable (under 0.05 mag) 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.