About HIP 117690
HIP 117690 is a rare variable star. It sits in the constellation Cas, shines at apparent magnitude 9.94 and has spectral type F9Ib.
Its spectrum reads F9Ib — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Rare variable star 43 EP
HIP 117690
RA 358.0293° · Dec 58.7417° · star
Score breakdown
· 6 badgesRare 50 pts → Epic
- Supergiant +18
- Strongly variable +10
- Variable star +5
- Never sets (northern circumpolar) +4
- Yellow-white F-type star +3
- A named variable star +3
Total score 43
7 more points to reach Epic.
Badges
- Variable star · +5
- Never sets (northern circumpolar) · +4
- Yellow-white F-type star · +3
- Supergiant · +18
- Strongly variable · +10
- A named variable star · +3
Trivia
Hard to believe
- True brightness. It pours out about 903.6 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 F9Ib — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
- Where it is in life. It is a supergiant, hundreds of times wider than the Sun.
- It changes. This star does not hold still: its brightness rises and falls on a rhythm of hours, days or years, either pulsing in size or being eclipsed by a companion.
Find it in the sky
- How to spot it. At magnitude 9.9 you'll want a small backyard telescope, over in Cassiopeia.
- 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 September — that's when to go looking.
Its true colour
- Its true colour. Measured through blue and visual filters it comes out orange (B−V 1.1) — cooler than the Sun, and the kind of star that burns steadily for tens of billions of years.
Properties
- absmag
- -10.06
- bv
- 1.14
- constellation
- Cas
- luminosity
- 920449.5718
- mag
- 9.94
- name
- HIP 117690
- spect
- F9Ib
- var amplitude
- 0.9
- var designation
- RY
- var max
- 9.426
- var min
- 10.326
How to see it
Look for HIP 117690 in the constellation Cas. At apparent magnitude 9.94, a small backyard telescope will bring it into view.
Like any astronomical target, HIP 117690 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 117690 is a rare variable star
HIP 117690 scores 43 points on Spacedle's rarity scale, which places it in the rare tier. Another 7 points would lift it into a rarer tier.
That score comes from 6 science badges — Variable star, Never sets (northern circumpolar), Yellow-white F-type star, Supergiant, Strongly variable and A named variable 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.