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Uncommon variable star 29 EP

HD 316285

RA 267.0585° · Dec -28.0148° · star

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Score breakdown

· 6 badges
29 pts · Uncommon
Uncommon 34 pts → Rare
  • Toward the galactic centre +8
  • Hot blue B-type star +6
  • Variable star +5
  • Gently variable +4
  • On the zodiac +3
  • A named variable star +3
Total score 29

5 more points to reach Rare.

Badges

  • Variable star · +5
  • Toward the galactic centre · +8
  • On the zodiac · +3
  • Hot blue B-type star · +6
  • Gently variable · +4
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 1.8 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 Be — 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 9.2 you'll want a small backyard telescope, over in Sagittarius.
  • Southern sky. It rides the southern half of the sky — an easier target the further south you are.
  • 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 orange (B−V 1.2) — cooler than the Sun, and the kind of star that burns steadily for tens of billions of years.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 4370 K, against the Sun's 5778 K.

Properties

absmag
-10.8
bv
1.17
constellation
Sgr
luminosity
1819700.8586
mag
9.2
name
HD 316285
spect
Be
var amplitude
0.13
var designation
V4375
var max
9.112
var min
9.242

About HD 316285

HD 316285 is an uncommon variable star. It sits in the constellation Sgr, shines at apparent magnitude 9.2 and has spectral type Be.

Its spectrum reads Be — 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 316285 in the constellation Sgr. At apparent magnitude 9.2, a small backyard telescope will bring it into view.

Like any astronomical target, HD 316285 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 316285 is an uncommon variable star

HD 316285 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 6 science badges — Variable star, Toward the galactic centre, On the zodiac, Hot blue B-type 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.