← Back to dex
Common star 16 EP

HD 171722

RA 280.6250° · Dec -70.3032° · star

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

Computing the sky for your location…

Score breakdown

· 4 badges
16 pts · Common
Common 22 pts → Uncommon
  • Hot blue B-type star +6
  • Blue-white star +5
  • Star +3
  • Main-sequence star +2
Total score 16

6 more points to reach Uncommon.

Badges

  • Star · +3
  • Hot blue B-type star · +6
  • Main-sequence star · +2
  • Blue-white star · +5

Trivia

What it actually is

  • Spectral class. Its spectrum reads B9V — 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.

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 7.2 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Pavo.
  • Southern sky only. So far south it never rises for most of the northern hemisphere. To see it you'd have to travel to Chile, South Africa or Australia.
  • 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. ≈ 14.8 million years at Voyager 1's speed (17 km/s).

Properties

absmag
0.189
bv
-0.024
constellation
Pav
dist ly
842.7803
luminosity
73.1813
mag
7.25
name
HD 171722
spect
B9V

About HD 171722

HD 171722 is a common star. It lies about 842.8 light-years from Earth, sits in the constellation Pav, shines at apparent magnitude 7.25 and has spectral type B9V.

Its spectrum reads B9V — 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 HD 171722 in the constellation Pav. At apparent magnitude 7.25, it is an easy target for binoculars.

Like any astronomical target, HD 171722 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 171722 is a common star

HD 171722 scores 16 points on Spacedle's rarity scale, which places it in the common tier. Another 6 points would lift it into a rarer tier.

That score comes from 4 science badges — Star, Hot blue B-type star, Main-sequence star and Blue-white 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.