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Common variable star 20 EP

HD 135297

RA 228.5875° · Dec 0.3696° · star

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Score breakdown

· 5 badges
20 pts · Common
Common 22 pts → Uncommon
  • 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 20

2 more points to reach Uncommon.

Badges

  • Variable star · +5
  • 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.

Find it in the sky

  • How to spot it. At magnitude 8 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Serpens.
  • 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 May — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out blue-white (B−V -0) — the hallmark of a surface far hotter than the Sun's.
  • Why no green stars. No star ever looks green: a surface hot enough to peak in green also floods out plenty of red and blue, and your eye blends the mixture back to white.

By the numbers

  • Surface temperature. Its colour puts the surface at roughly 10150 K, against the Sun's 5778 K.

Properties

absmag
-12.01
bv
-0.002
constellation
Ser
luminosity
5546257.1296
mag
7.99
name
HD 135297
spect
A0p
var amplitude
0.04
var designation
FI
var max
7.965
var min
8.005

Nearby objects

About HD 135297

HD 135297 is a common variable star. It sits in the constellation Ser, shines at apparent magnitude 7.99 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 HD 135297 in the constellation Ser. At apparent magnitude 7.99, it is an easy target for binoculars.

Like any astronomical target, HD 135297 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 135297 is a common variable star

HD 135297 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, 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.