← Back to dex
Trash star 14 EP

HD 172522

RA 280.0942° · Dec 8.8685° · star

Loading sky survey…
🌌 View in 3D star map
Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 3 badges
14 pts · Trash
Trash 15 pts → Common
  • Giant star +6
  • White A-type star +5
  • Star +3
Total score 14

1 more point to reach Common.

Badges

  • Star · +3
  • White A-type star · +5
  • Giant star · +6

Trivia

What it actually is

  • Spectral class. Its spectrum reads A2III — 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.

Find it in the sky

  • How to spot it. At magnitude 6.9 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Ophiuchus.
  • 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 July — that's when to go looking.

Its true colour

  • Its true colour. Measured through blue and visual filters it comes out brilliant white (B−V 0.2) — hotter and whiter than the Sun, the colour of Sirius or Vega.
  • 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 8010 K, against the Sun's 5778 K.

Properties

absmag
-13.07
bv
0.22
constellation
Oph
luminosity
14723125.0243
mag
6.93
name
HD 172522
spect
A2III

Nearby objects

About HD 172522

HD 172522 is a trash star. It sits in the constellation Oph, shines at apparent magnitude 6.93 and has spectral type A2III.

Its spectrum reads A2III — 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 172522 in the constellation Oph. At apparent magnitude 6.93, it is an easy target for binoculars.

Like any astronomical target, HD 172522 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 172522 is a trash star

HD 172522 scores 14 points on Spacedle's rarity scale, which places it in the trash tier. Another 1 point would lift it into a rarer tier.

That score comes from 3 science badges — Star, White A-type star and Giant 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.