Uncommon variable star 25 EP

HD 101794

RA 175.6056° · Dec -62.4771° · star

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Score breakdown

· 6 badges

25 pts · Uncommon

Uncommon 34 pts → Rare

Hot blue B-type star +6
Variable star +5
Blue-white star +5
Gently variable +4
A named variable star +3
Main-sequence star +2

Total score 25

9 more points to reach Rare.

Badges

Variable star · +5
Hot blue B-type star · +6
Main-sequence star · +2
Blue-white star · +5
Gently variable · +4
A named variable star · +3

Trivia

Hard to believe

True brightness. It pours out about 2.8 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 B1.5V — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.
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 8.7 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Centaurus.
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.

Its true colour

Its true colour. Measured through blue and visual filters it comes out blue-white (B−V -0) — the hallmark of a surface far hotter than the Sun's.

Properties

absmag: -11.3
bv: -0.007
constellation: Cen
luminosity: 2884031.5031
mag: 8.7
name: HD 101794
spect: B1.5V
var amplitude: 0.22
var designation: V916
var max: 8.607
var min: 8.827

Nearby objects

About HD 101794

HD 101794 is an uncommon variable star. It sits in the constellation Cen, shines at apparent magnitude 8.7 and has spectral type B1.5V.

Its spectrum reads B1.5V — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.

How to see it

Look for HD 101794 in the constellation Cen. At apparent magnitude 8.7, it is an easy target for binoculars.

Like any astronomical target, HD 101794 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 101794 is an uncommon variable star

HD 101794 scores 25 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 9 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, Hot blue B-type star, Main-sequence star, Blue-white 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.