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Rare variable star 48 EP

HIP 87668

RA 268.6089° · Dec -23.2360° · star

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Score breakdown

· 8 badges
48 pts · Rare
Rare 50 pts → Epic
  • Strongly variable +10
  • Toward the galactic centre +8
  • Deep red star +8
  • Red dwarf +6
  • Variable star +5
  • Cool red M-type star +5
  • On the zodiac +3
  • A named variable star +3
Total score 48

2 more points to reach Epic.

Badges

  • Variable star · +5
  • Toward the galactic centre · +8
  • On the zodiac · +3
  • Cool red M-type star · +5
  • Deep red star · +8
  • Red dwarf · +6
  • Strongly variable · +10
  • A named variable star · +3

Trivia

Hard to believe

  • True brightness. It pours out about 1.7 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 M5 — 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 9.2 you'll want a small backyard telescope, over in Sagittarius.
  • 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 June — 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 2.4) — one of the coolest surfaces a star can have while still fusing.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 2830 K, against the Sun's 5778 K.

Properties

absmag
-10.76
bv
2.372
constellation
Sgr
luminosity
1753880.5018
mag
9.24
name
HIP 87668
spect
M5
var amplitude
0.51
var designation
V774
var max
9.058
var min
9.568

About HIP 87668

HIP 87668 is a rare variable star. It sits in the constellation Sgr, shines at apparent magnitude 9.24 and has spectral type M5.

Its spectrum reads M5 — 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 HIP 87668 in the constellation Sgr. At apparent magnitude 9.24, a small backyard telescope will bring it into view.

Like any astronomical target, HIP 87668 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 HIP 87668 is a rare variable star

HIP 87668 scores 48 points on Spacedle's rarity scale, which places it in the rare tier. Another 2 points would lift it into a rarer tier.

That score comes from 8 science badges — Variable star, Toward the galactic centre, On the zodiac, Cool red M-type star, Deep red star, Red dwarf, 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.