About HD 236989
HD 236989 is a common star. It sits in the constellation Cas, shines at apparent magnitude 9.02 and has spectral type F7III.
Its spectrum reads F7III — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Common star 16 EP
HD 236989
RA 40.9051° · Dec 60.6084° · star
Score breakdown
· 4 badgesCommon 22 pts → Uncommon
- Giant star +6
- Never sets (northern circumpolar) +4
- Star +3
- Yellow-white F-type star +3
Total score 16
6 more points to reach Uncommon.
Badges
- Star · +3
- Never sets (northern circumpolar) · +4
- Yellow-white F-type star · +3
- Giant star · +6
Trivia
Hard to believe
- True brightness. It pours out about 2.1 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 F7III — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
- Where it is in life. It is a giant. It has already exhausted its core hydrogen and swollen up enormously in response.
Find it in the sky
- How to spot it. At magnitude 9 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 orange (B−V 0.8) — cooler than the Sun, and the kind of star that burns steadily for tens of billions of years.
- 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
- -10.98
- bv
- 0.849
- constellation
- Cas
- luminosity
- 2147830.4741
- mag
- 9.02
- name
- HD 236989
- spect
- F7III
Nearby objects
- Uncommon J0243+6027 pulsar · 0.2° away
- Uncommon HD 16506 variable star · 0.3° away
- Uncommon HD 17086 star · 0.4° away
- Uncommon J0248+6021 pulsar · 0.6° away
- Rare HIP 12469 variable star · 0.7° away
- Rare HD 16429 variable star · 0.8° away
- Rare HD 16778 star · 0.8° away
- Common HIP 12293 star · 0.8° away
How to see it
Look for HD 236989 in the constellation Cas. At apparent magnitude 9.02, a small backyard telescope will bring it into view.
Like any astronomical target, HD 236989 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 236989 is a common star
HD 236989 scores 16 points on Spacedle's rarity scale, which places it in the common tier. Another 6 points would lift it into a rarer tier.
That score comes from 4 science badges — Star, Never sets (northern circumpolar), Yellow-white F-type star and Giant 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.