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Rare variable star 39 EP

HD 18949

RA 45.2171° · Dec -50.6422° · star

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Score breakdown

· 5 badges
39 pts · Rare
Rare 50 pts → Epic
  • Dramatic variable (over 2 magnitudes) +20
  • Red dwarf +6
  • Variable star +5
  • Cool red M-type star +5
  • A named variable star +3
Total score 39

11 more points to reach Epic.

Badges

  • Variable star · +5
  • Cool red M-type star · +5
  • Red dwarf · +6
  • Dramatic variable (over 2 magnitudes) · +20
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 1.1 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 M2/M3e — an M-type red star — and M stars are the silent majority: roughly three of every four stars in the galaxy are one.
  • 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 9.7 you'll want a small backyard telescope, over in Horologium.
  • 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 November — 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 4340 K, against the Sun's 5778 K.

Properties

absmag
-10.3
bv
1.183
constellation
Hor
luminosity
1148153.6215
mag
9.7
name
HD 18949
spect
M2/M3e
var amplitude
3.29
var designation
T
var max
8.345
var min
11.635

About HD 18949

HD 18949 is a rare variable star. It sits in the constellation Hor, shines at apparent magnitude 9.7 and has spectral type M2/M3e.

Its spectrum reads M2/M3e — 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 18949 in the constellation Hor. At apparent magnitude 9.7, a small backyard telescope will bring it into view.

Like any astronomical target, HD 18949 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 18949 is a rare variable star

HD 18949 scores 39 points on Spacedle's rarity scale, which places it in the rare tier. Another 11 points would lift it into a rarer tier.

That score comes from 5 science badges — Variable star, Cool red M-type star, Red dwarf, Dramatic variable (over 2 magnitudes) 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.