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Common variable star 20 EP

HD 21094

RA 51.0645° · Dec 1.3567° · star

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Score breakdown

· 5 badges
20 pts · Common
Common 22 pts → Uncommon
  • Variable star +5
  • White A-type star +5
  • Gently variable +4
  • On the zodiac +3
  • A named variable star +3
Total score 20

2 more points to reach Uncommon.

Badges

  • Variable star · +5
  • On the zodiac · +3
  • White A-type star · +5
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads A2 — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.
  • 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 8.4 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Taurus.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • Best time of year. It stands highest in the middle of the night around November — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Getting there

  • Aboard Voyager 1. ≈ 8.8 million years at Voyager 1's speed (17 km/s).

Properties

absmag
2.495
bv
0.273
constellation
Tau
dist ly
499.4733
luminosity
8.7498
mag
8.42
name
HD 21094
spect
A2
var amplitude
0.38
var designation
V1121
var max
8.365
var min
8.745

About HD 21094

HD 21094 is a common variable star. It lies about 499.5 light-years from Earth, sits in the constellation Tau, shines at apparent magnitude 8.42 and has spectral type A2.

Its spectrum reads A2 — an A-type star: white-hot, typically about twice the Sun's mass, and the class most of the sky's famous bright stars belong to.

How to see it

Look for HD 21094 in the constellation Tau. At apparent magnitude 8.42, it is an easy target for binoculars.

Like any astronomical target, HD 21094 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 21094 is a common variable star

HD 21094 scores 20 points on Spacedle's rarity scale, which places it in the common tier. Another 2 points would lift it into a rarer tier.

That score comes from 5 science badges — Variable star, On the zodiac, White A-type star, 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.