Rare variable star 37 EP

HIP 81157

RA 248.6287° · Dec -63.1336° · star

Loading sky survey…

🌌 View in 3D star map

Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 6 badges

37 pts · Rare

Rare 50 pts → Epic

Strongly variable +10
Sun-like G-type star +8
Distant (over 1,000 light-years) +6
Variable star +5
Subgiant (leaving the main sequence) +5
A named variable star +3

Total score 37

13 more points to reach Epic.

Badges

Variable star · +5
Distant (over 1,000 light-years) · +6
Sun-like G-type star · +8
Subgiant (leaving the main sequence) · +5
Strongly variable · +10
A named variable star · +3

Trivia

What it actually is

Spectral class. Its spectrum reads G2IV: — a G-type star: the very same spectral class as our own Sun.
Where it is in life. It is a subgiant, caught in the act of leaving the main sequence as the hydrogen in its core runs out.
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 9.7 you'll want a small backyard telescope, over in Triangulum Australe.
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 May — that's when to go looking.

Could we get there?

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

Properties

absmag: 0.202
bv: 0.76
constellation: TrA
dist ly: 2588.5397
luminosity: 72.3103
mag: 9.7
name: HIP 81157
spect: G2IV:
var amplitude: 0.73
var designation: RT
var max: 9.433
var min: 10.163

Nearby objects

About HIP 81157

HIP 81157 is a rare variable star. It lies about 2,588.5 light-years from Earth, sits in the constellation TrA, shines at apparent magnitude 9.7 and has spectral type G2IV:.

Its spectrum reads G2IV: — a G-type star: the very same spectral class as our own Sun.

How to see it

Look for HIP 81157 in the constellation TrA. At apparent magnitude 9.7, a small backyard telescope will bring it into view.

Like any astronomical target, HIP 81157 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 HIP 81157 is a rare variable star

HIP 81157 scores 37 points on Spacedle's rarity scale, which places it in the rare tier. Another 13 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, Distant (over 1,000 light-years), Sun-like G-type star, Subgiant (leaving the main sequence), 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.