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Trash star 11 EP

21 Oph

RA 252.8539° · Dec 1.2159° · star

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Score breakdown

· 2 badges
11 pts · Trash
Trash 15 pts → Common
  • Naked-eye visible +8
  • Star +3
Total score 11

4 more points to reach Common.

Badges

  • Star · +3
  • Naked-eye visible · +8

Trivia

Could we get there?

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

Getting there

  • Aboard Voyager 1. ≈ 6.7 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 591.5 thousand years even at the Parker Solar Probe's 192 km/s.
  • At 10% light speed. ≈ 3788 years in a starship at a tenth of light speed.
  • Distance. 379 light-years from Earth.

Look-back time

  • Look-back time. The light you'd see left around the year 1647.

Saying hello

  • Say hello. A radio message and its reply would take 758 years round-trip.

Properties

absmag
0.185
bv
0.055
constellation
Oph
dist ly
378.8106
mag
5.51
name
21 Oph
spect
A2Vs

About 21 Oph

21 Oph is a trash star. It lies about 378.8 light-years from Earth, sits in the constellation Oph, shines at apparent magnitude 5.51 and has spectral type A2Vs.

21 Oph is a trash star worth 11 points across 2 science badges. Explore its facts, badges and place on the sky map, then add it to your dex on Spacedle.

How to see it

Look for 21 Oph in the constellation Oph. At apparent magnitude 5.51, it can be glimpsed with the unaided eye under dark skies.

Like any astronomical target, 21 Oph 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 21 Oph is a trash star

21 Oph scores 11 points on Spacedle's rarity scale, which places it in the trash tier. Another 4 points would lift it into a rarer tier.

That score comes from 2 science badges — Star and Naked-eye visible — 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.