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Common variable star 21 EP

HD 99325

RA 171.2740° · Dec -60.7346° · star

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Score breakdown

· 4 badges
21 pts · Common
Common 22 pts → Uncommon
  • Strongly variable +10
  • Variable star +5
  • Orange K-type star +3
  • A named variable star +3
Total score 21

1 more point to reach Uncommon.

Badges

  • Variable star · +5
  • Orange K-type star · +3
  • Strongly variable · +10
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 2.7 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 K0 — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions 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 8.8 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 orange (B−V 1) — cooler than the Sun, and the kind of star that burns steadily for tens of billions of years.
  • 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
-11.24
bv
0.977
constellation
Cen
luminosity
2728977.7828
mag
8.76
name
HD 99325
spect
K0
var amplitude
0.57
var designation
AY
var max
8.554
var min
9.124

Nearby objects

About HD 99325

HD 99325 is a common variable star. It sits in the constellation Cen, shines at apparent magnitude 8.76 and has spectral type K0.

Its spectrum reads K0 — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions of years.

How to see it

Look for HD 99325 in the constellation Cen. At apparent magnitude 8.76, it is an easy target for binoculars.

Like any astronomical target, HD 99325 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 99325 is a common variable star

HD 99325 scores 21 points on Spacedle's rarity scale, which places it in the common tier. Another 1 point would lift it into a rarer tier.

That score comes from 4 science badges — Variable star, Orange K-type 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.