About HIP 12817
HIP 12817 is an uncommon variable star. It sits in the constellation Cas, shines at apparent magnitude 10.84 and has spectral type G0.2:.
Its spectrum reads G0.2: — a G-type star: the very same spectral class as our own Sun.
Uncommon variable star 30 EP
HIP 12817
RA 41.1805° · Dec 61.4647° · star
Score breakdown
· 5 badgesUncommon 34 pts → Rare
- Strongly variable +10
- Sun-like G-type star +8
- Variable star +5
- Never sets (northern circumpolar) +4
- A named variable star +3
Total score 30
4 more points to reach Rare.
Badges
- Variable star · +5
- Never sets (northern circumpolar) · +4
- Sun-like G-type star · +8
- Strongly variable · +10
- A named variable star · +3
Trivia
Hard to believe
- True brightness. It pours out about 394.5 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 G0.2: — a G-type star: the very same spectral class as our own 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 10.8 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 1.1) — cooler than the Sun, and the kind of star that burns steadily for tens of billions of years.
By the numbers
- Surface temperature. Its colour puts the surface at roughly 4560 K, against the Sun's 5778 K.
Properties
- absmag
- -9.16
- bv
- 1.08
- constellation
- Cas
- luminosity
- 401790.8108
- mag
- 10.84
- name
- HIP 12817
- spect
- G0.2:
- var amplitude
- 0.65
- var designation
- DF
- var max
- 10.533
- var min
- 11.183
Nearby objects
How to see it
Look for HIP 12817 in the constellation Cas. At apparent magnitude 10.84, a small backyard telescope will bring it into view.
Like any astronomical target, HIP 12817 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 12817 is an uncommon variable star
HIP 12817 scores 30 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 4 points would lift it into a rarer tier.
That score comes from 5 science badges — Variable star, Never sets (northern circumpolar), Sun-like G-type star, 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.