About HD 221894
HD 221894 is a trash star. It sits in the constellation Aqr, shines at apparent magnitude 9.32 and has spectral type F3/F5IV.
Its spectrum reads F3/F5IV — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Trash star 14 EP
HD 221894
RA 353.9872° · Dec -21.6422° · star
Score breakdown
· 4 badgesTrash 15 pts → Common
- Subgiant (leaving the main sequence) +5
- Star +3
- On the zodiac +3
- Yellow-white F-type star +3
Total score 14
1 more point to reach Common.
Badges
- Star · +3
- On the zodiac · +3
- Yellow-white F-type star · +3
- Subgiant (leaving the main sequence) · +5
Trivia
Hard to believe
- True brightness. It pours out about 1.6 million times as much light as the Sun. It only looks ordinary because it is so far away.
What it actually is
- Spectral class. Its spectrum reads F3/F5IV — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Find it in the sky
- How to spot it. At magnitude 9.3 you'll want a small backyard telescope, over in Aquarius.
- Southern sky. It rides the southern half of the sky — an easier target the further south you are.
- Best time of year. It stands highest in the middle of the night around September — that's when to go looking.
Its true colour
- Its true colour. Measured through blue and visual filters it comes out yellow-white (B−V 0.5) — a shade brighter and crisper than our own Sun.
- Why no green stars. No star ever looks green: a surface hot enough to peak in green also floods out plenty of red and blue, and your eye blends the mixture back to white.
By the numbers
- Surface temperature. Its colour puts the surface at roughly 6490 K, against the Sun's 5778 K.
Properties
- absmag
- -10.68
- bv
- 0.479
- constellation
- Aqr
- luminosity
- 1629296.0326
- mag
- 9.32
- name
- HD 221894
- spect
- F3/F5IV
How to see it
Look for HD 221894 in the constellation Aqr. At apparent magnitude 9.32, a small backyard telescope will bring it into view.
Like any astronomical target, HD 221894 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 221894 is a trash star
HD 221894 scores 14 points on Spacedle's rarity scale, which places it in the trash tier. Another 1 point would lift it into a rarer tier.
That score comes from 4 science badges — Star, On the zodiac, Yellow-white F-type star and Subgiant (leaving the main sequence) — 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.