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Uncommon variable star 26 EP

HD 305784

RA 164.4612° · Dec -60.7421° · star

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Score breakdown

· 4 badges
26 pts · Uncommon
Uncommon 34 pts → Rare
  • Strongly variable +10
  • Sun-like G-type star +8
  • Variable star +5
  • A named variable star +3
Total score 26

8 more points to reach Rare.

Badges

  • Variable star · +5
  • Sun-like G-type star · +8
  • Strongly variable · +10
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 1 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 G0 — a G-type star: the very same spectral class as our own Sun.
  • 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 9.8 you'll want a small backyard telescope, over in Carina.
  • 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 0.9) — 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
-10.22
bv
0.872
constellation
Car
luminosity
1066596.1212
mag
9.78
name
HD 305784
spect
G0
var amplitude
0.58
var designation
CY
var max
9.412
var min
9.992

Nearby objects

About HD 305784

HD 305784 is an uncommon variable star. It sits in the constellation Car, shines at apparent magnitude 9.78 and has spectral type G0.

Its spectrum reads G0 — a G-type star: the very same spectral class as our own Sun.

How to see it

Look for HD 305784 in the constellation Car. At apparent magnitude 9.78, a small backyard telescope will bring it into view.

Like any astronomical target, HD 305784 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 305784 is an uncommon variable star

HD 305784 scores 26 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 8 points would lift it into a rarer tier.

That score comes from 4 science badges — Variable star, Sun-like G-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.