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Epic variable star 51 EP

HD 30551

RA 71.5397° · Dec -49.2458° · star

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Score breakdown

· 6 badges
51 pts · Epic
Epic 78 pts → Anomaly
  • Dramatic variable (over 2 magnitudes) +20
  • Bright giant +12
  • Deep red star +8
  • Variable star +5
  • Orange K-type star +3
  • A named variable star +3
Total score 51

27 more points to reach Anomaly.

Badges

  • Variable star · +5
  • Orange K-type star · +3
  • Bright giant · +12
  • Deep red star · +8
  • Dramatic variable (over 2 magnitudes) · +20
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads K2/K3II:pe — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions of years.
  • 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 7.5 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Pictor.
  • 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 December — 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 1.5) — one of the coolest surfaces a star can have while still fusing.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 3840 K, against the Sun's 5778 K.

What's in a name

  • Its catalogue. The HD number is from the Henry Draper Catalogue, in which Annie Jump Cannon personally classified the spectra of nearly 400,000 stars — still the largest such feat by one person.

Properties

absmag
-12.52
bv
1.472
constellation
Pic
luminosity
8871560.1204
mag
7.48
name
HD 30551
spect
K2/K3II:pe
var amplitude
2.32
var designation
R
var max
6.353
var min
8.673

About HD 30551

HD 30551 is an epic variable star. It sits in the constellation Pic, shines at apparent magnitude 7.48 and has spectral type K2/K3II:pe.

Its spectrum reads K2/K3II:pe — a K-type star. Orange K dwarfs are the marathon runners of the galaxy, burning steadily for tens of billions of years.

How to see it

Look for HD 30551 in the constellation Pic. At apparent magnitude 7.48, it is an easy target for binoculars.

Like any astronomical target, HD 30551 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 30551 is an epic variable star

HD 30551 scores 51 points on Spacedle's rarity scale, which places it in the epic tier. Another 27 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, Orange K-type star, Bright giant, Deep red star, 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.