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Trash star 8 EP

HD 21715

RA 52.5312° · Dec -4.8549° · star

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Score breakdown

· 2 badges
8 pts · Trash
Trash 15 pts → Common
  • White A-type star +5
  • Star +3
Total score 8

7 more points to reach Common.

Badges

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

Trivia

What it actually is

  • Spectral class. Its spectrum reads A3 — 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.

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 8.9 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Eridanus.
  • 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 November — 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. ≈ 10.7 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 953.7 thousand years even at the Parker Solar Probe's 192 km/s.

Properties

absmag
2.508
bv
0.294
constellation
Eri
dist ly
610.779
luminosity
8.6457
mag
8.87
name
HD 21715
spect
A3

About HD 21715

HD 21715 is a trash star. It lies about 610.8 light-years from Earth, sits in the constellation Eri, shines at apparent magnitude 8.87 and has spectral type A3.

Its spectrum reads A3 — 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 21715 in the constellation Eri. At apparent magnitude 8.87, it is an easy target for binoculars.

Like any astronomical target, HD 21715 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 21715 is a trash star

HD 21715 scores 8 points on Spacedle's rarity scale, which places it in the trash tier. Another 7 points would lift it into a rarer tier.

That score comes from 2 science badges — Star and White A-type 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.