About HD 164315
HD 164315 is an uncommon star. It sits in the constellation Sgr, shines at apparent magnitude 10.57 and has spectral type F7IV/V.
Its spectrum reads F7IV/V — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
Uncommon star 22 EP
HD 164315
RA 270.4452° · Dec -25.6264° · star
Score breakdown
· 5 badgesUncommon 34 pts → Rare
- Toward the galactic centre +8
- Subgiant (leaving the main sequence) +5
- Star +3
- On the zodiac +3
- Yellow-white F-type star +3
Total score 22
12 more points to reach Rare.
Badges
- Star · +3
- Toward the galactic centre · +8
- On the zodiac · +3
- Yellow-white F-type star · +3
- Subgiant (leaving the main sequence) · +5
Trivia
Hard to believe
- True brightness. It pours out about 505.8 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 F7IV/V — an F-type star — a little hotter, whiter and shorter-lived than the Sun.
- Where it is in life. It is a subgiant, caught in the act of leaving the main sequence as the hydrogen in its core runs out.
Find it in the sky
- How to spot it. At magnitude 10.6 you'll want a small backyard telescope, over in Sagittarius.
- 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 June — that's when to go looking.
Its true colour
- Its true colour. Measured through blue and visual filters it comes out yellow (B−V 0.6) — 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
- -9.43
- bv
- 0.648
- constellation
- Sgr
- luminosity
- 515228.6446
- mag
- 10.57
- name
- HD 164315
- spect
- F7IV/V
How to see it
Look for HD 164315 in the constellation Sgr. At apparent magnitude 10.57, a small backyard telescope will bring it into view.
Like any astronomical target, HD 164315 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 164315 is an uncommon star
HD 164315 scores 22 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 12 points would lift it into a rarer tier.
That score comes from 5 science badges — Star, Toward the galactic centre, On the zodiac, Yellow-white F-type star and Subgiant (leaving the main sequence) — 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.