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Rare variable star 47 EP

HD 28257

RA 67.6737° · Dec 57.4117° · star

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Score breakdown

· 7 badges
47 pts · Rare
Rare 50 pts → Epic
  • Bright giant +12
  • Strongly variable +10
  • Deep red star +8
  • Variable star +5
  • Cool red M-type star +5
  • Never sets (northern circumpolar) +4
  • A named variable star +3
Total score 47

3 more points to reach Epic.

Badges

  • Variable star · +5
  • Never sets (northern circumpolar) · +4
  • Cool red M-type star · +5
  • Bright giant · +12
  • Deep red star · +8
  • Strongly variable · +10
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 5.1 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 M4II-IIIvar — an M-type red star — and M stars are the silent majority: roughly three of every four stars in the galaxy are one.
  • Where it is in life. It is a bright giant, well on its way to the largest stars there are.
  • 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 8.1 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Camelopardalis.
  • Northern sky. It rides the northern half of the sky — an easier target the further north you are.
  • Best time of year. It stands highest in the middle of the night around November — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out deep orange-red (B−V 1.4) — one of the coolest surfaces a star can have while still fusing.

Properties

absmag
-11.94
bv
1.449
constellation
Cam
luminosity
5199959.9653
mag
8.06
name
HD 28257
spect
M4II-IIIvar
var amplitude
0.96
var designation
RV
var max
7.567
var min
8.527

About HD 28257

HD 28257 is a rare variable star. It sits in the constellation Cam, shines at apparent magnitude 8.06 and has spectral type M4II-IIIvar.

Its spectrum reads M4II-IIIvar — an M-type red star — and M stars are the silent majority: roughly three of every four stars in the galaxy are one.

How to see it

Look for HD 28257 in the constellation Cam. At apparent magnitude 8.06, it is an easy target for binoculars.

Like any astronomical target, HD 28257 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 28257 is a rare variable star

HD 28257 scores 47 points on Spacedle's rarity scale, which places it in the rare tier. Another 3 points would lift it into a rarer tier.

That score comes from 7 science badges — Variable star, Never sets (northern circumpolar), Cool red M-type star, Bright giant, Deep red 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.