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Epic exoplanet 65 EP

HD 210277 b

RA 332.3748° · Dec -7.5506° · exoplanet

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Score breakdown

· 5 badges
65 pts · Epic
Epic 78 pts → Anomaly
  • In the habitable zone +30
  • Found before the year 2000 +18
  • Orbits a Sun-like star +8
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 65

13 more points to reach Anomaly.

Badges

  • Confirmed exoplanet · +5
  • In the habitable zone · +30
  • Gas giant · +4
  • Orbits a Sun-like star · +8
  • Found before the year 2000 · +18

Trivia

What makes it special

  • Goldilocks zone. Sits where it's neither too hot nor too cold — liquid water could exist on a surface here.

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.
  • What the zone means. The habitable zone is only about temperature: it is the band where liquid water could survive on a surface. It is a promising address, not evidence of anything living.

Sense of scale

  • In perspective. Inside our stellar backyard: every radio broadcast humanity has ever made has already swept past it.

Find it in the sky

  • How to spot it. At magnitude 6.5 it is just past naked-eye reach — ordinary binoculars will pull it in.
  • Seen from everywhere. It sits almost on the celestial equator, so it can be seen from essentially anywhere on Earth.
  • Best time of year. It stands highest in the middle of the night around August — that's when to go looking.

Properties

density gcc
0.896
diameter km
173484.32
discovery facility
W. M. Keck Observatory
discovery method
Radial Velocity
discovery year
1998
dist ly
69.4663
eccentricity
0.48
eq temp k
259.86
habitable zone
yes
host star teff
5538
insolation
0.7275
mag
6.5435
mass earth
410.0007
name
HD 210277 b
orbital period days
442.19
radius earth
13.6
semi major au
1.13
spect
G0 V
sys num planets
1
sys num stars
1

Nearby objects

About HD 210277 b

HD 210277 b is an epic exoplanet. It lies about 69.5 light-years from Earth, shines at apparent magnitude 6.54, has spectral type G0 V and has an equilibrium temperature near 260 K.

Sits where it's neither too hot nor too cold — liquid water could exist on a surface here.

How to see it

At apparent magnitude 6.54, it is an easy target for binoculars.

Like any astronomical target, HD 210277 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 HD 210277 b is an epic exoplanet

HD 210277 b scores 65 points on Spacedle's rarity scale, which places it in the epic tier. Another 13 points would lift it into a rarer tier.

That score comes from 5 science badges — Confirmed exoplanet, In the habitable zone, Gas giant, Orbits a Sun-like star and Found before the year 2000 — 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.