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Epic variable star 53 EP

HD 107805

RA 185.9071° · Dec -61.6291° · star

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Score breakdown

· 7 badges
53 pts · Epic
Epic 78 pts → Anomaly
  • Supergiant +18
  • Strongly variable +10
  • Under the Southern Cross +8
  • Distant (over 1,000 light-years) +6
  • Variable star +5
  • Yellow-white F-type star +3
  • A named variable star +3
Total score 53

25 more points to reach Anomaly.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • Under the Southern Cross · +8
  • Yellow-white F-type star · +3
  • Supergiant · +18
  • Strongly variable · +10
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads F7Ib/II — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
  • Where it is in life. It is a supergiant, hundreds of times wider than the Sun.
  • 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 6.9 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.

Properties

absmag
-1.627
bv
0.67
constellation
Cru
dist ly
1647.2525
luminosity
389.7625
mag
6.89
name
HD 107805
spect
F7Ib/II
var amplitude
0.75
var designation
R
var max
6.397
var min
7.147

About HD 107805

HD 107805 is an epic variable star. It lies about 1,647.3 light-years from Earth, sits in the constellation Cru, shines at apparent magnitude 6.89 and has spectral type F7Ib/II.

Its spectrum reads F7Ib/II — an F-type star — a little hotter, whiter and shorter-lived than the Sun.

How to see it

Look for HD 107805 in the constellation Cru. At apparent magnitude 6.89, it is an easy target for binoculars.

Like any astronomical target, HD 107805 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 107805 is an epic variable star

HD 107805 scores 53 points on Spacedle's rarity scale, which places it in the epic tier. Another 25 points would lift it into a rarer tier.

That score comes from 7 science badges — Variable star, Distant (over 1,000 light-years), Under the Southern Cross, Yellow-white F-type star, Supergiant, Strongly 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.