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Uncommon variable star 31 EP

HD 104810

RA 181.0171° · Dec -64.5389° · star

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Score breakdown

· 6 badges
31 pts · Uncommon
Uncommon 34 pts → Rare
  • Under the Southern Cross +8
  • Distant (over 1,000 light-years) +6
  • Variable star +5
  • White A-type star +5
  • Gently variable +4
  • A named variable star +3
Total score 31

3 more points to reach Rare.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • Under the Southern Cross · +8
  • White A-type star · +5
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads Ap Si — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.
  • 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 Crux.
  • Southern sky only. So far south it never rises for most of the northern hemisphere. To see it you'd have to travel to Chile, South Africa or Australia.
  • Best time of year. It stands highest in the middle of the night around March — that's when to go looking.

Could we get there?

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

Getting there

  • Aboard Voyager 1. ≈ 31.7 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-1.362
bv
0.029
constellation
Cru
dist ly
1801.9669
luminosity
305.3515
mag
7.35
name
HD 104810
spect
Ap Si
var amplitude
0.07
var designation
DH
var max
7.313
var min
7.383

About HD 104810

HD 104810 is an uncommon variable star. It lies about 1,802 light-years from Earth, sits in the constellation Cru, shines at apparent magnitude 7.35 and has spectral type Ap Si.

Its spectrum reads Ap Si — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.

How to see it

Look for HD 104810 in the constellation Cru. At apparent magnitude 7.35, it is an easy target for binoculars.

Like any astronomical target, HD 104810 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 104810 is an uncommon variable star

HD 104810 scores 31 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 3 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, Distant (over 1,000 light-years), Under the Southern Cross, White A-type star, 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.