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Common exoplanet 15 EP

HD 154857 b

RA 257.8162° · Dec -56.6810° · exoplanet

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Score breakdown

· 3 badges
15 pts · Common
Common 24 pts → Uncommon
  • Multi-planet system +6
  • Confirmed exoplanet +5
  • Gas giant +4
Total score 15

9 more points to reach Uncommon.

Badges

  • Confirmed exoplanet · +5
  • Gas giant · +4
  • Multi-planet system · +6

Trivia

Could we get there?

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

Getting there

  • Aboard Voyager 1. ≈ 3.6 million years at Voyager 1's speed (17 km/s).
  • Fastest probe ever. ≈ 323.1 thousand years even at the Parker Solar Probe's 192 km/s.
  • At 10% light speed. ≈ 2069 years in a starship at a tenth of light speed.
  • Distance. 207 light-years from Earth.

Look-back time

  • Look-back time. The light you'd see left around the year 1819.

Saying hello

  • Say hello. A radio message and its reply would take 414 years round-trip.

Standing on it

  • A year here. A full year lasts just 409 Earth days.

By the numbers

  • Size. About 13.3× the width of Earth.
  • Volume. About 2353 Earths could fit inside it.
  • Mass. Roughly 779× Earth's mass — about 2.5 Jupiters.
  • Your weight. You'd weigh about 4.4× your Earth weight standing here.
  • Temperature. A scorching 87°C on average.

How we found it

  • Discovery. Found by Anglo-Australian Telescope using the radial velocity method.

Cosmic context

  • Crowded system. One of at least 2 planets orbiting its star.

Properties

density gcc
1.82
discovery facility
Anglo-Australian Telescope
discovery method
Radial Velocity
dist ly
206.9401
eccentricity
0.46
eq temp k
359.86
insolation
2.7638
mass earth
778.6835
name
HD 154857 b
orbital period days
408.6
radius earth
13.3
sys num planets
2

About HD 154857 b

HD 154857 b is a common exoplanet. It lies about 206.9 light-years from Earth, has an equilibrium temperature near 360 K, spans roughly 13.3 Earth radii and weighs about 778.68 Earth masses.

One of at least 2 planets orbiting its star.

How to see it

Like any astronomical target, HD 154857 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 154857 b is a common exoplanet

HD 154857 b scores 15 points on Spacedle's rarity scale, which places it in the common tier. Another 9 points would lift it into a rarer tier.

That score comes from 3 science badges — Confirmed exoplanet, Gas giant and Multi-planet system — 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.

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Sky imagery and survey data courtesy of Aladin Lite & CDS, Strasbourg. Object data from the NASA Exoplanet Archive, JPL Small-Body Database, and the ATNF Pulsar Catalogue.