← Back to dex
Rare variable star 49 EP

HD 139492

RA 232.3944° · Dec 78.6334° · star

Loading sky survey…
🌌 View in 3D star map
Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 7 badges
49 pts · Rare
Rare 50 pts → Epic
  • Dramatic variable (over 2 magnitudes) +20
  • Distant (over 1,000 light-years) +6
  • Red dwarf +6
  • Variable star +5
  • Cool red M-type star +5
  • Never sets (northern circumpolar) +4
  • A named variable star +3
Total score 49

1 more point to reach Epic.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • Never sets (northern circumpolar) · +4
  • Cool red M-type star · +5
  • Red dwarf · +6
  • Dramatic variable (over 2 magnitudes) · +20
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads M6e-M9e — 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.

Sense of scale

  • In perspective. Far away by human standards, yet still a local address inside the Milky Way's spiral arms.

Find it in the sky

  • How to spot it. At magnitude 9.2 you'll want a small backyard telescope, over in Ursa Minor.
  • Never sets. So far north that from Britain, Canada or northern Europe it never dips below the horizon — it is up every clear night of the year.
  • Best time of year. It stands highest in the middle of the night around May — that's when to go looking.

Could we get there?

  • Verdict. Impossible with our current technology — and the next millennium of it.

Getting there

  • Aboard Voyager 1. ≈ 43.1 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-0.141
bv
1.088
constellation
UMi
dist ly
2452.3008
luminosity
99.1745
mag
9.24
name
HD 139492
spect
M6e-M9e
var amplitude
2.82
var designation
S
var max
7.705
var min
10.525

About HD 139492

HD 139492 is a rare variable star. It lies about 2,452.3 light-years from Earth, sits in the constellation UMi, shines at apparent magnitude 9.24 and has spectral type M6e-M9e.

Its spectrum reads M6e-M9e — 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 139492 in the constellation UMi. At apparent magnitude 9.24, a small backyard telescope will bring it into view.

Like any astronomical target, HD 139492 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 139492 is a rare variable star

HD 139492 scores 49 points on Spacedle's rarity scale, which places it in the rare tier. Another 1 point would lift it into a rarer tier.

That score comes from 7 science badges — Variable star, Distant (over 1,000 light-years), Never sets (northern circumpolar), 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.