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Common exoplanet 17 EP

HAT-P-15 b

RA 66.2481° · Dec 39.4606° · exoplanet

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Score breakdown

· 3 badges
17 pts · Common
Common 22 pts → Uncommon
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 17

5 more points to reach Uncommon.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Orbits a Sun-like star · +8

Trivia

What it actually is

  • Hugging its star. It orbits closer to its star than Mercury does to the Sun, completing a lap in less time than Mercury takes.
  • What it is made of. Too light to be solid rock and too heavy to be all gas: most likely a deep global ocean or a thick steamy envelope over a rocky core.

Sense of scale

  • In perspective. Far away by human standards, yet still a local address inside the Milky Way's spiral arms.

Find it in the sky

  • How to spot it. At magnitude 12.4 it is far too faint for the eye: this one belongs to cameras and long exposures.
  • 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 November — that's when to go looking.

Could we get there?

  • Verdict. Hopelessly far for any craft humanity can build today.

Getting there

  • Aboard Voyager 1. ≈ 11 million years at Voyager 1's speed (17 km/s).

Properties

density gcc
1.96
diameter km
151563.3005
discovery facility
HATNet
discovery method
Transit
discovery year
2010
dist ly
627.9025
eccentricity
0.19
eq temp k
904
host star teff
5568
inclination
89.1
insolation
79.7578
mag
12.41
mass earth
616.5902
name
HAT-P-15 b
orbital period days
10.8635
radius earth
11.8815
semi major au
0.0965
spect
G5
sys num planets
1
sys num stars
1

About HAT-P-15 b

HAT-P-15 b is a common exoplanet. It lies about 627.9 light-years from Earth, shines at apparent magnitude 12.41, has spectral type G5 and has an equilibrium temperature near 904 K.

It orbits closer to its star than Mercury does to the Sun, completing a lap in less time than Mercury takes.

How to see it

At apparent magnitude 12.41, it takes a larger telescope or a long-exposure image to capture.

Like any astronomical target, HAT-P-15 b 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 HAT-P-15 b is a common exoplanet

HAT-P-15 b scores 17 points on Spacedle's rarity scale, which places it in the common tier. Another 5 points would lift it into a rarer tier.

That score comes from 3 science badges — Confirmed exoplanet, Gas giant and Orbits a Sun-like 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.