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Uncommon variable star 28 EP

17 Com

RA 187.2279° · Dec 25.9129° · star

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Score breakdown

· 6 badges
28 pts · Uncommon
Uncommon 34 pts → Rare
  • Naked-eye visible +8
  • Variable star +5
  • White A-type star +5
  • Blue-white star +5
  • A named variable star +3
  • Barely variable (under 0.05 mag) +2
Total score 28

6 more points to reach Rare.

Badges

  • Variable star · +5
  • Naked-eye visible · +8
  • White A-type star · +5
  • Blue-white star · +5
  • Barely variable (under 0.05 mag) · +2
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads A0p — 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 5.3 you can see it with your own eyes from a dark site, over in Coma Berenices.
  • 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 March — 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. ≈ 4.2 million years at Voyager 1's speed (17 km/s).

Properties

absmag
0.977
bv
-0.056
constellation
Com
dist ly
237.723
luminosity
35.416
mag
5.29
name
17 Com
spect
A0p
var amplitude
0.03
var designation
AI
var max
5.268
var min
5.298

About 17 Com

17 Com is an uncommon variable star. It lies about 237.7 light-years from Earth, sits in the constellation Com, shines at apparent magnitude 5.29 and has spectral type A0p.

Its spectrum reads A0p — 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 17 Com in the constellation Com. At apparent magnitude 5.29, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 17 Com 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 17 Com is an uncommon variable star

17 Com scores 28 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 6 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, Naked-eye visible, White A-type star, Blue-white star, 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.