About HIP 20573
HIP 20573 is a trash star. It sits in the constellation Per, shines at apparent magnitude 8.64 and has spectral type F2IV.
Its spectrum reads F2IV — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Trash star 11 EP
HIP 20573
RA 66.1093° · Dec 34.3174° · star
Score breakdown
· 3 badgesTrash 15 pts → Common
- Subgiant (leaving the main sequence) +5
- Star +3
- Yellow-white F-type star +3
Total score 11
4 more points to reach Common.
Badges
- Star · +3
- Yellow-white F-type star · +3
- Subgiant (leaving the main sequence) · +5
Trivia
Hard to believe
- True brightness. It pours out about 3 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 F2IV — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
- Where it is in life. It is a subgiant, caught in the act of leaving the main sequence as the hydrogen in its core runs out.
Find it in the sky
- How to spot it. At magnitude 8.6 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Perseus.
- Northern sky. It rides the northern half of the sky — an easier target the further north you are.
- Best time of year. It stands highest in the middle of the night around November — 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 0.4) — 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
- -11.36
- bv
- 0.401
- constellation
- Per
- luminosity
- 3047894.9896
- mag
- 8.64
- name
- HIP 20573
- spect
- F2IV
How to see it
Look for HIP 20573 in the constellation Per. At apparent magnitude 8.64, it is an easy target for binoculars.
Like any astronomical target, HIP 20573 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 HIP 20573 is a trash star
HIP 20573 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 3 science badges — Star, 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.