Rare variable star 44 EP

HD 151055

RA 252.5275° · Dec -67.7828° · star

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Score breakdown

· 5 badges

44 pts · Rare

Rare 50 pts → Epic

Carbon star (sooty red) +24
Deep red star +8
Variable star +5
Gently variable +4
A named variable star +3

Total score 44

6 more points to reach Epic.

Badges

Variable star · +5
Carbon star (sooty red) · +24
Deep red star · +8
Gently variable · +4
A named variable star · +3

Trivia

Hard to believe

True brightness. It pours out about 4.3 million times as much light as the Sun. It only looks ordinary because it is so far away.

What it actually is

Spectral class. Its spectrum reads C6.4v — a carbon star, wrapped in so much soot that its light is filtered to a deep ruby red.
Where it is in life. It is on the main sequence, quietly fusing hydrogen in its core exactly as the Sun does.
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.

Find it in the sky

How to spot it. At magnitude 8.2 it is just past naked-eye reach — ordinary binoculars will pull it in, 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 June — that's when to go looking.

Its true colour

Its true colour. Measured through blue and visual filters it comes out deep orange-red (B−V 2.5) — one of the coolest surfaces a star can have while still fusing.

Properties

absmag: -11.75
bv: 2.453
constellation: TrA
luminosity: 4365158.3224
mag: 8.25
name: HD 151055
spect: C6.4v
var amplitude: 0.18
var designation: V
var max: 8.151
var min: 8.331

Nearby objects

About HD 151055

HD 151055 is a rare variable star. It sits in the constellation TrA, shines at apparent magnitude 8.25 and has spectral type C6.4v.

Its spectrum reads C6.4v — a carbon star, wrapped in so much soot that its light is filtered to a deep ruby red.

How to see it

Look for HD 151055 in the constellation TrA. At apparent magnitude 8.25, it is an easy target for binoculars.

Like any astronomical target, HD 151055 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 151055 is a rare variable star

HD 151055 scores 44 points on Spacedle's rarity scale, which places it in the rare tier. Another 6 points would lift it into a rarer tier.

That score comes from 5 science badges — Variable star, Carbon star (sooty red), Deep red 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.