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Rare variable star 35 EP

HD 140155

RA 235.1888° · Dec 38.7186° · star

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Score breakdown

· 7 badges
35 pts · Rare
Rare 50 pts → Epic
  • Deep red star +8
  • Distant (over 1,000 light-years) +6
  • Red dwarf +6
  • Variable star +5
  • Cool red M-type star +5
  • A named variable star +3
  • Barely variable (under 0.05 mag) +2
Total score 35

15 more points to reach Epic.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • Cool red M-type star · +5
  • Deep red star · +8
  • Red dwarf · +6
  • Barely variable (under 0.05 mag) · +2
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads M0 — 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 7.8 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Corona Borealis.
  • 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 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. ≈ 37.5 million years at Voyager 1's speed (17 km/s).

Properties

absmag
-1.297
bv
1.557
constellation
CrB
dist ly
2131.7387
luminosity
287.6074
mag
7.78
name
HD 140155
spect
M0
var amplitude
0.05
var designation
SW
var max
7.758
var min
7.808

About HD 140155

HD 140155 is a rare variable star. It lies about 2,131.7 light-years from Earth, sits in the constellation CrB, shines at apparent magnitude 7.78 and has spectral type M0.

Its spectrum reads M0 — 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 140155 in the constellation CrB. At apparent magnitude 7.78, it is an easy target for binoculars.

Like any astronomical target, HD 140155 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 140155 is a rare variable star

HD 140155 scores 35 points on Spacedle's rarity scale, which places it in the rare tier. Another 15 points would lift it into a rarer tier.

That score comes from 7 science badges — Variable star, Distant (over 1,000 light-years), Cool red M-type star, Deep red star, Red dwarf, Barely variable (under 0.05 mag) 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.