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Uncommon variable star 28 EP

HR 2545

RA 102.5973° · Dec -31.7061° · star

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Score breakdown

· 6 badges
28 pts · Uncommon
Uncommon 34 pts → Rare
  • Naked-eye visible +8
  • Hot blue B-type star +6
  • Variable star +5
  • Gently variable +4
  • A named variable star +3
  • Main-sequence star +2
Total score 28

6 more points to reach Rare.

Badges

  • Variable star · +5
  • Naked-eye visible · +8
  • Hot blue B-type star · +6
  • Main-sequence star · +2
  • Gently variable · +4
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads B3V — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.
  • Where it is in life. It is on the main sequence, quietly fusing hydrogen in its core exactly as the Sun does.
  • 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 5.7 you can see it with your own eyes from a dark site, over in Canis Major.
  • 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 January — that's when to go looking.

Could we get there?

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

Properties

absmag
-0.756
bv
0.094
constellation
CMa
dist ly
649.7132
luminosity
174.7431
mag
5.74
name
HR 2545
spect
B3V
var amplitude
0.07
var designation
HZ
var max
5.701
var min
5.771

About HR 2545

HR 2545 is an uncommon variable star. It lies about 649.7 light-years from Earth, sits in the constellation CMa, shines at apparent magnitude 5.74 and has spectral type B3V.

Its spectrum reads B3V — a blue-white B-type star, with a surface tens of thousands of degrees hot and a life measured in tens of millions of years.

How to see it

Look for HR 2545 in the constellation CMa. At apparent magnitude 5.74, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, HR 2545 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 HR 2545 is an uncommon variable star

HR 2545 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, Hot blue B-type star, Main-sequence 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.