About HIP 77997
HIP 77997 is a common variable star. It sits in the constellation Ser, shines at apparent magnitude 11.61 and has spectral type F2.
Its spectrum reads F2 — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Common variable star 21 EP
HIP 77997
RA 238.9182° · Dec 7.9888° · star
Score breakdown
· 4 badgesCommon 22 pts → Uncommon
- Strongly variable +10
- Variable star +5
- Yellow-white F-type star +3
- A named variable star +3
Total score 21
1 more point to reach Uncommon.
Badges
- Variable star · +5
- Yellow-white F-type star · +3
- Strongly variable · +10
- A named variable star · +3
Trivia
Hard to believe
- True brightness. It pours out about 194.1 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 F2 — an F-type star — a little hotter, whiter and shorter-lived 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 11.6 you'll want a small backyard telescope, over in Serpens.
- Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
- Best time of year. It stands highest in the middle of the night around May — that's when to go looking.
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.
How we came to know it
- Cosmic yardstick. Variable stars are how we measured the universe. In 1912 Henrietta Leavitt showed that a pulsating star's rhythm reveals its true brightness — turning these stars into distance markers.
Properties
- absmag
- -8.39
- constellation
- Ser
- luminosity
- 197696.964
- mag
- 11.61
- name
- HIP 77997
- spect
- F2
- var amplitude
- 0.96
- var designation
- AT
- var max
- 10.973
- var min
- 11.933
How to see it
Look for HIP 77997 in the constellation Ser. At apparent magnitude 11.61, a small backyard telescope will bring it into view.
Like any astronomical target, HIP 77997 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 77997 is a common variable star
HIP 77997 scores 21 points on Spacedle's rarity scale, which places it in the common tier. Another 1 point would lift it into a rarer tier.
That score comes from 4 science badges — Variable star, Yellow-white F-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.