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Uncommon star 26 EP

HD 165210

RA 271.5863° · Dec -34.3151° · star

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Score breakdown

· 5 badges
26 pts · Uncommon
Uncommon 34 pts → Rare
  • Toward the galactic centre +8
  • Hot blue B-type star +6
  • Giant star +6
  • Star +3
  • On the zodiac +3
Total score 26

8 more points to reach Rare.

Badges

  • Star · +3
  • Toward the galactic centre · +8
  • On the zodiac · +3
  • Hot blue B-type star · +6
  • Giant star · +6

Trivia

What it actually is

  • Spectral class. Its spectrum reads B5III/IV — 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 giant. It has already exhausted its core hydrogen and swollen up enormously in response.

Find it in the sky

  • How to spot it. At magnitude 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.

What's in a name

  • Its catalogue. The HD number is from the Henry Draper Catalogue, in which Annie Jump Cannon personally classified the spectra of nearly 400,000 stars — still the largest such feat by one person.

Properties

absmag
-12.01
constellation
Sgr
luminosity
5546257.1296
mag
7.99
name
HD 165210
spect
B5III/IV

About HD 165210

HD 165210 is an uncommon star. It sits in the constellation Sgr, shines at apparent magnitude 7.99 and has spectral type B5III/IV.

Its spectrum reads B5III/IV — 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 165210 in the constellation Sgr. At apparent magnitude 7.99, it is an easy target for binoculars.

Like any astronomical target, HD 165210 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 165210 is an uncommon star

HD 165210 scores 26 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 8 points would lift it into a rarer tier.

That score comes from 5 science badges — Star, Toward the galactic centre, On the zodiac, Hot blue B-type star and Giant 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.