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Trash star 9 EP

HD 21643

RA 52.4388° · Dec 5.8004° · star

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Score breakdown

· 3 badges
9 pts · Trash
Trash 15 pts → Common
  • Star +3
  • On the zodiac +3
  • Yellow-white F-type star +3
Total score 9

6 more points to reach Common.

Badges

  • Star · +3
  • On the zodiac · +3
  • Yellow-white F-type star · +3

Trivia

What it actually is

  • Spectral class. Its spectrum reads F5 — an F-type star — a little hotter, whiter and shorter-lived than the Sun.

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 8.5 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Taurus.
  • 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. ≈ 11 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 979.4 thousand years even at the Parker Solar Probe's 192 km/s.

Properties

absmag
2.1
bv
0.478
constellation
Tau
dist ly
627.2231
luminosity
12.5893
mag
8.52
name
HD 21643
spect
F5

About HD 21643

HD 21643 is a trash star. It lies about 627.2 light-years from Earth, sits in the constellation Tau, shines at apparent magnitude 8.52 and has spectral type F5.

Its spectrum reads F5 — an F-type star — a little hotter, whiter and shorter-lived than the Sun.

How to see it

Look for HD 21643 in the constellation Tau. At apparent magnitude 8.52, it is an easy target for binoculars.

Like any astronomical target, HD 21643 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 21643 is a trash star

HD 21643 scores 9 points on Spacedle's rarity scale, which places it in the trash tier. Another 6 points would lift it into a rarer tier.

That score comes from 3 science badges — Star, On the zodiac and Yellow-white F-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.