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Rare variable star 39 EP

HR 7552

RA 297.9608° · Dec -39.8744° · star

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Score breakdown

· 8 badges
39 pts · Rare
Rare 50 pts → Epic
  • Naked-eye visible +8
  • Toward the galactic centre +8
  • Variable star +5
  • White A-type star +5
  • Blue-white star +5
  • On the zodiac +3
  • A named variable star +3
  • Barely variable (under 0.05 mag) +2
Total score 39

11 more points to reach Epic.

Badges

  • Variable star · +5
  • Naked-eye visible · +8
  • Toward the galactic centre · +8
  • On the zodiac · +3
  • 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 Sagittarius.
  • 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 July — 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. ≈ 5.3 million years at Voyager 1's speed (17 km/s).

Properties

absmag
0.491
bv
-0.045
constellation
Sgr
dist ly
301.4379
luminosity
55.4115
mag
5.32
name
HR 7552
spect
A0p
var amplitude
0.04
var designation
V3961
var max
5.286
var min
5.326

About HR 7552

HR 7552 is a rare variable star. It lies about 301.4 light-years from Earth, sits in the constellation Sgr, shines at apparent magnitude 5.32 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 HR 7552 in the constellation Sgr. At apparent magnitude 5.32, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, HR 7552 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 7552 is a rare variable star

HR 7552 scores 39 points on Spacedle's rarity scale, which places it in the rare tier. Another 11 points would lift it into a rarer tier.

That score comes from 8 science badges — Variable star, Naked-eye visible, Toward the galactic centre, On the zodiac, 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.