About HD 263139
HD 263139 is an uncommon variable star. It sits in the constellation Gem, shines at apparent magnitude 11.35 and has spectral type G5.
Its spectrum reads G5 — a G-type star: the very same spectral class as our own Sun.
Uncommon variable star 29 EP
HD 263139
RA 101.5380° · Dec 34.4147° · star
Score breakdown
· 5 badgesUncommon 34 pts → Rare
- Strongly variable +10
- Sun-like G-type star +8
- Variable star +5
- On the zodiac +3
- A named variable star +3
Total score 29
5 more points to reach Rare.
Badges
- Variable star · +5
- On the zodiac · +3
- Sun-like G-type star · +8
- Strongly variable · +10
- A named variable star · +3
Trivia
Hard to believe
- True brightness. It pours out about 246.6 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 G5 — 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 11.3 you'll want a small backyard telescope, over in Gemini.
- 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 January — that's when to go looking.
What's in a name
- Its catalogue. The HD number is from the Henry Draper Catalogue, in which Annie Jump Cannon personally classified the spectra of nearly 400,000 stars — still the largest such feat by one person.
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
- -8.65
- constellation
- Gem
- luminosity
- 251188.6432
- mag
- 11.35
- name
- HD 263139
- spect
- G5
- var amplitude
- 0.52
- var designation
- GX
- var max
- 11.237
- var min
- 11.757
How to see it
Look for HD 263139 in the constellation Gem. At apparent magnitude 11.35, a small backyard telescope will bring it into view.
Like any astronomical target, HD 263139 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 263139 is an uncommon variable star
HD 263139 scores 29 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 5 points would lift it into a rarer tier.
That score comes from 5 science badges — Variable star, On the zodiac, 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.