About HR 4912
HR 4912 is an uncommon variable star. It sits in the constellation Hya, shines at apparent magnitude 6.73 and has spectral type F3Ia.
Its spectrum reads F3Ia — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Uncommon variable star 33 EP
HR 4912
RA 194.1255° · Dec -26.4603° · star
Score breakdown
· 5 badgesUncommon 34 pts → Rare
- Supergiant +18
- Variable star +5
- Gently variable +4
- Yellow-white F-type star +3
- A named variable star +3
Total score 33
1 more point to reach Rare.
Badges
- Variable star · +5
- Yellow-white F-type star · +3
- Supergiant · +18
- Gently variable · +4
- A named variable star · +3
Trivia
What it actually is
- Spectral class. Its spectrum reads F3Ia — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
- Where it is in life. It is a luminous supergiant — among the largest and rarest stars in the galaxy.
- 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 6.7 it is just past naked-eye reach — ordinary binoculars will pull it in, over in Hydra.
- Southern sky. It rides the southern half of the sky — an easier target the further south you are.
- Best time of year. It stands highest in the middle of the night around April — that's when to go looking.
Its true colour
- Its true colour. Measured through blue and visual filters it comes out yellow (B−V 0.7) — almost exactly the Sun's own shade — a stellar twin in colour, if not in size.
- 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
- -13.27
- bv
- 0.728
- constellation
- Hya
- luminosity
- 17701089.5832
- mag
- 6.73
- name
- HR 4912
- spect
- F3Ia
- var amplitude
- 0.26
- var designation
- LN
- var max
- 6.629
- var min
- 6.889
How to see it
Look for HR 4912 in the constellation Hya. At apparent magnitude 6.73, it is an easy target for binoculars.
Like any astronomical target, HR 4912 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 HR 4912 is an uncommon variable star
HR 4912 scores 33 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 1 point would lift it into a rarer tier.
That score comes from 5 science badges — Variable star, Yellow-white F-type star, Supergiant, Gently 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.