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Uncommon variable star 29 EP

HIP 33163

RA 103.5513° · Dec -7.5958° · star

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Score breakdown

· 5 badges
29 pts · Uncommon
Uncommon 34 pts → Rare
  • Strongly variable +10
  • Hot blue B-type star +6
  • Variable star +5
  • Blue-white star +5
  • A named variable star +3
Total score 29

5 more points to reach Rare.

Badges

  • Variable star · +5
  • Hot blue B-type star · +6
  • Blue-white star · +5
  • Strongly variable · +10
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 515.2 thousand 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 B9pvar — 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.
  • 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 10.6 you'll want a small backyard telescope, over in Monoceros.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • Best time of year. It stands highest in the middle of the night around January — 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.
  • Why no green stars. No star ever looks green: a surface hot enough to peak in green also floods out plenty of red and blue, and your eye blends the mixture back to white.

Properties

absmag
-9.45
bv
-0.007
constellation
Mon
luminosity
524807.4602
mag
10.55
name
HIP 33163
spect
B9pvar
var amplitude
0.65
var designation
RU
var max
10.484
var min
11.134

About HIP 33163

HIP 33163 is an uncommon variable star. It sits in the constellation Mon, shines at apparent magnitude 10.55 and has spectral type B9pvar.

Its spectrum reads B9pvar — 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 HIP 33163 in the constellation Mon. At apparent magnitude 10.55, a small backyard telescope will bring it into view.

Like any astronomical target, HIP 33163 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 33163 is an uncommon variable star

HIP 33163 scores 29 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 5 points would lift it into a rarer tier.

That score comes from 5 science badges — Variable star, Hot blue B-type star, Blue-white star, 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.