About HIP 7173
HIP 7173 is a trash star. It sits in the constellation Cas and shines at apparent magnitude 10.6.
Its colour puts the surface at roughly 5430 K, against the Sun's 5778 K.
Trash star 7 EP
HIP 7173
RA 23.1217° · Dec 63.8216° · star
Score breakdown
· 2 badgesTrash 15 pts → Common
- Never sets (northern circumpolar) +4
- Star +3
Total score 7
8 more points to reach Common.
Badges
- Star · +3
- Never sets (northern circumpolar) · +4
Trivia
Hard to believe
- True brightness. It pours out about 492 thousand times as much light as the Sun. It only looks ordinary because it is so far away.
Find it in the sky
- How to spot it. At magnitude 10.6 you'll want a small backyard telescope, over in Cassiopeia.
- Never sets. So far north that from Britain, Canada or northern Europe it never dips below the horizon — it is up every clear night of the year.
- Best time of year. It stands highest in the middle of the night around October — that's when to go looking.
Its true colour
- Its true colour. Measured through blue and visual filters it comes out yellow (B−V 0.8) — almost exactly the Sun's own shade — a stellar twin in colour, if not in size.
- 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 5430 K, against the Sun's 5778 K.
What's in a name
- Its catalogue. The HIP number comes from Hipparcos, the ESA satellite that between 1989 and 1993 pinned down 118,000 stars precisely enough to triangulate their distances.
Properties
- absmag
- -9.4
- bv
- 0.751
- constellation
- Cas
- luminosity
- 501187.2336
- mag
- 10.6
- name
- HIP 7173
How to see it
Look for HIP 7173 in the constellation Cas. At apparent magnitude 10.6, a small backyard telescope will bring it into view.
Like any astronomical target, HIP 7173 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 7173 is a trash star
HIP 7173 scores 7 points on Spacedle's rarity scale, which places it in the trash tier. Another 8 points would lift it into a rarer tier.
That score comes from 2 science badges — Star and Never sets (northern circumpolar) — 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.