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Uncommon variable star 26 EP

HD 11729

RA 28.8799° · Dec 17.1894° · star

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Score breakdown

· 6 badges
26 pts · Uncommon
Uncommon 34 pts → Rare
  • Red dwarf +6
  • Variable star +5
  • Cool red M-type star +5
  • Gently variable +4
  • On the zodiac +3
  • A named variable star +3
Total score 26

8 more points to reach Rare.

Badges

  • Variable star · +5
  • On the zodiac · +3
  • Cool red M-type star · +5
  • Red dwarf · +6
  • Gently variable · +4
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 4.2 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 M... — 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 8.3 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Aries.
  • 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 October — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out orange (B−V 1.4) — 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 4000 K, against the Sun's 5778 K.

Properties

absmag
-11.72
bv
1.371
constellation
Ari
luminosity
4246195.6395
mag
8.28
name
HD 11729
spect
M...
var amplitude
0.3
var designation
ZZ
var max
8.182
var min
8.482

About HD 11729

HD 11729 is an uncommon variable star. It sits in the constellation Ari, shines at apparent magnitude 8.28 and has spectral type M....

Its spectrum reads M... — 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 11729 in the constellation Ari. At apparent magnitude 8.28, it is an easy target for binoculars.

Like any astronomical target, HD 11729 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 11729 is an uncommon variable star

HD 11729 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 6 science badges — Variable star, On the zodiac, Cool red M-type star, Red dwarf, 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.