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Uncommon variable star 27 EP

HR 2557

RA 103.8111° · Dec 43.9100° · star

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Score breakdown

· 6 badges
27 pts · Uncommon
Uncommon 34 pts → Rare
  • Distant (over 1,000 light-years) +6
  • Giant star +6
  • Variable star +5
  • White A-type star +5
  • A named variable star +3
  • Barely variable (under 0.05 mag) +2
Total score 27

7 more points to reach Rare.

Badges

  • Variable star · +5
  • Distant (over 1,000 light-years) · +6
  • White A-type star · +5
  • Giant star · +6
  • Barely variable (under 0.05 mag) · +2
  • A named variable star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads A9III — 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.
  • Where it is in life. It is a giant. It has already exhausted its core hydrogen and swollen up enormously in response.
  • 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 6.2 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Auriga.
  • 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 January — that's when to go looking.

Could we get there?

  • Verdict. Impossible with our current technology — and the next millennium of it.

Properties

absmag
-1.301
bv
0.314
constellation
Aur
dist ly
1012.9068
luminosity
288.6689
mag
6.16
name
HR 2557
spect
A9III
var amplitude
0.02
var designation
V352
var max
6.151
var min
6.171

About HR 2557

HR 2557 is an uncommon variable star. It lies about 1,012.9 light-years from Earth, sits in the constellation Aur, shines at apparent magnitude 6.16 and has spectral type A9III.

Its spectrum reads A9III — 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 HR 2557 in the constellation Aur. At apparent magnitude 6.16, it is an easy target for binoculars.

Like any astronomical target, HR 2557 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 2557 is an uncommon variable star

HR 2557 scores 27 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 7 points would lift it into a rarer tier.

That score comes from 6 science badges — Variable star, Distant (over 1,000 light-years), White A-type star, Giant 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.