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Rare exoplanet 37 EP

XO-1 b

RA 240.5493° · Dec 28.1696° · exoplanet

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Score breakdown

· 5 badges
37 pts · Rare
Rare 50 pts → Epic
  • Hot Jupiter +10
  • Tidally locked +10
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 37

13 more points to reach Epic.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Hot Jupiter · +10
  • Tidally locked · +10
  • Orbits a Sun-like star · +8

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

  • 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. 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 11.3 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 May — that's when to go looking.

Could we get there?

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

Properties

density gcc
0.64
diameter km
163002.0402
discovery facility
XO
discovery method
Transit
discovery year
2006
dist ly
533.4379
eccentricity
0
eq temp k
1210
host star teff
5750
inclination
88.81
insolation
321.85
mag
11.251
mass earth
263.7989
name
XO-1 b
orbital period days
3.9415
radius earth
12.7783
semi major au
0.0488
spect
G1 V
sys num planets
1
sys num stars
1
tidally locked
yes
tidally locked inferred
yes

About XO-1 b

XO-1 b is a rare exoplanet. It lies about 533.4 light-years from Earth, shines at apparent magnitude 11.25, has spectral type G1 V and has an equilibrium temperature near 1,210 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 11.25, a small backyard telescope will bring it into view.

Like any astronomical target, XO-1 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 XO-1 b is a rare exoplanet

XO-1 b scores 37 points on Spacedle's rarity scale, which places it in the rare tier. Another 13 points would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, Gas giant, Hot Jupiter, Tidally locked 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.