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Trash star 3 EP

HD 21729

RA 52.8781° · Dec 34.6795° · star

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Score breakdown

· 1 badge
3 pts · Trash
Trash 15 pts → Common
  • Star +3
Total score 3

12 more points to reach Common.

Badges

  • Star · +3

Trivia

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Getting there

  • Aboard Voyager 1. ≈ 13.3 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 1.2 million years even at the Parker Solar Probe's 192 km/s.
  • At 10% light speed. ≈ 7585 years in a starship at a tenth of light speed.
  • Distance. 759 light-years from Earth.

Look-back time

  • Look-back time. The light you'd see left around the year 1267.

Saying hello

  • Say hello. A radio message and its reply would take 1517 years round-trip.

Properties

absmag
2.247
bv
0.558
constellation
Per
dist ly
758.5022
mag
9.08
name
HD 21729
spect
G0

About HD 21729

HD 21729 is a trash star. It lies about 758.5 light-years from Earth, sits in the constellation Per, shines at apparent magnitude 9.08 and has spectral type G0.

HD 21729 is a trash star worth 3 points across 1 science badge. Explore its facts, badges and place on the sky map, then add it to your dex on Spacedle.

How to see it

Look for HD 21729 in the constellation Per. At apparent magnitude 9.08, a small backyard telescope will bring it into view.

Like any astronomical target, HD 21729 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 21729 is a trash star

HD 21729 scores 3 points on Spacedle's rarity scale, which places it in the trash tier. Another 12 points would lift it into a rarer tier.

That score comes from 1 science badge — 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.

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Sky imagery and survey data courtesy of Aladin Lite & CDS, Strasbourg. Object data from the NASA Exoplanet Archive, JPL Small-Body Database, and the ATNF Pulsar Catalogue.