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Rare exoplanet 34 EP

BD+42 2315 b

RA 187.5888° · Dec 41.2696° · exoplanet

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Score breakdown

· 5 badges
34 pts · Rare
Rare 50 pts → Epic
  • Hot Jupiter +10
  • Eccentric orbit +9
  • Distant (over 1,000 light-years) +6
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 34

16 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Distant (over 1,000 light-years) · +6
  • Gas giant · +4
  • Hot Jupiter · +10
  • Eccentric orbit · +9

Trivia

Hard to believe

  • It would float. It is less dense than water. Drop it in a big enough ocean and the whole world would bob on the surface.

What it actually is

  • What it is made of. Lighter than Neptune — a puffed-up ball of hydrogen and helium with no surface anywhere on it to stand on.

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 9.7 you'll want a small backyard telescope.
  • 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 March — that's when to go looking.

Could we get there?

  • Verdict. Impossible with our current technology — and the next millennium of it.

Getting there

  • Aboard Voyager 1. ≈ 35 million years at Voyager 1's speed (17 km/s).

Properties

density gcc
0.335
diameter km
181138.04
discovery facility
McDonald Observatory
discovery method
Radial Velocity
discovery year
2023
dist ly
1991.8836
eccentricity
0.73
eq temp k
1247.58
host star teff
4500
insolation
335.1294
mag
9.723
mass earth
174.8056
name
BD+42 2315 b
orbital period days
123.05
radius earth
14.2
semi major au
0.54
sys num planets
1
sys num stars
1

About BD+42 2315 b

BD+42 2315 b is a rare exoplanet. It lies about 1,991.9 light-years from Earth, shines at apparent magnitude 9.72, has an equilibrium temperature near 1,248 K and spans roughly 14.2 Earth radii.

Lighter than Neptune — a puffed-up ball of hydrogen and helium with no surface anywhere on it to stand on.

How to see it

At apparent magnitude 9.72, a small backyard telescope will bring it into view.

Like any astronomical target, BD+42 2315 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 BD+42 2315 b is a rare exoplanet

BD+42 2315 b scores 34 points on Spacedle's rarity scale, which places it in the rare tier. Another 16 points would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, Distant (over 1,000 light-years), Gas giant, Hot Jupiter and Eccentric orbit — 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.