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Uncommon variable star 32 EP

HR 6902

RA 276.4117° · Dec 8.0320° · star

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Score breakdown

· 6 badges
32 pts · Uncommon
Uncommon 34 pts → Rare
  • Naked-eye visible +8
  • Sun-like G-type star +8
  • Giant star +6
  • Variable star +5
  • A named variable star +3
  • Barely variable (under 0.05 mag) +2
Total score 32

2 more points to reach Rare.

Badges

  • Variable star · +5
  • Naked-eye visible · +8
  • Sun-like G-type star · +8
  • Giant star · +6
  • Barely variable (under 0.05 mag) · +2
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads G8III-IV+.. — a G-type star: the very same spectral class as our own Sun.
  • Where it is in life. It is a giant. It has already exhausted its core hydrogen and swollen up enormously in response.
  • 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 5.6 you can see it with your own eyes from a dark site, over in Ophiuchus.
  • 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 June — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Properties

absmag
-1.275
bv
0.884
constellation
Oph
dist ly
787.8164
luminosity
281.8383
mag
5.64
name
HR 6902
spect
G8III-IV+..
var amplitude
0.03
var designation
V2291
var max
5.628
var min
5.658

About HR 6902

HR 6902 is an uncommon variable star. It lies about 787.8 light-years from Earth, sits in the constellation Oph, shines at apparent magnitude 5.64 and has spectral type G8III-IV+...

Its spectrum reads G8III-IV+.. — a G-type star: the very same spectral class as our own Sun.

How to see it

Look for HR 6902 in the constellation Oph. At apparent magnitude 5.64, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, HR 6902 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 HR 6902 is an uncommon variable star

HR 6902 scores 32 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 2 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, Naked-eye visible, Sun-like G-type star, Giant 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.