About HD 221996
HD 221996 is a trash star. It sits in the constellation Scl, shines at apparent magnitude 10.02 and has spectral type F5V.
Its spectrum reads F5V — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Trash star 8 EP
HD 221996
RA 354.2580° · Dec -25.4349° · star
Score breakdown
· 3 badgesTrash 15 pts → Common
- Star +3
- Yellow-white F-type star +3
- Main-sequence star +2
Total score 8
7 more points to reach Common.
Badges
- Star · +3
- Yellow-white F-type star · +3
- Main-sequence star · +2
Trivia
Hard to believe
- True brightness. It pours out about 839.5 thousand 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 F5V — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
- Where it is in life. It is on the main sequence, quietly fusing hydrogen in its core exactly as the Sun does.
Find it in the sky
- How to spot it. At magnitude 10 you'll want a small backyard telescope, over in Sculptor.
- 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.
Properties
- absmag
- -9.98
- bv
- 0.478
- constellation
- Scl
- luminosity
- 855066.7129
- mag
- 10.02
- name
- HD 221996
- spect
- F5V
How to see it
Look for HD 221996 in the constellation Scl. At apparent magnitude 10.02, a small backyard telescope will bring it into view.
Like any astronomical target, HD 221996 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 221996 is a trash star
HD 221996 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 3 science badges — Star, Yellow-white F-type star and Main-sequence 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.