About TOI-1173 b
TOI-1173 b is an uncommon exoplanet. It lies about 431.7 light-years from Earth, has an equilibrium temperature near 868 K, spans roughly 9.19 Earth radii and weighs about 27.4 Earth masses.
So low-density it would float on water.
Uncommon exoplanet 25 EP
TOI-1173 b
RA 197.6831° · Dec 70.7680° · exoplanet
Score breakdown
· 4 badgesUncommon 33 pts → Rare
- Puffy low-density world +12
- Confirmed exoplanet +5
- Gas giant +4
- Found by TESS +4
Total score 25
8 more points to reach Rare.
Badges
- Confirmed exoplanet · +5
- Gas giant · +4
- Puffy low-density world · +12
- Found by TESS · +4
Trivia
What makes it special
- Cotton-candy planet. So low-density it would float on water.
Could we get there?
- Verdict. Hopelessly far for any craft humanity can build today.
Getting there
- Aboard Voyager 1. ≈ 7.6 million years at Voyager 1's speed (17 km/s).
- Fastest probe ever. ≈ 674 thousand years even at the Parker Solar Probe's 192 km/s.
- At 10% light speed. ≈ 4317 years in a starship at a tenth of light speed.
- Distance. 432 light-years from Earth.
Look-back time
- Look-back time. The light you'd see left around the year 1594.
Saying hello
- Say hello. A radio message and its reply would take 863 years round-trip.
Standing on it
- A year here. A full year lasts just 7.1 Earth days.
By the numbers
- Size. About 9.2× the width of Earth.
- Volume. About 776 Earths could fit inside it.
- Mass. About 27.4× the mass of Earth.
- Your weight. You'd weigh about 0.3× your Earth weight standing here.
- Density. Less dense than water — drop it in a big enough ocean and it would float.
- Temperature. Around 595°C — hotter than a self-cleaning oven.
How we found it
- Discovery. Found by Transiting Exoplanet Survey Satellite (TESS) using the transit method.
Properties
- density gcc
- 0.195
- discovery facility
- Transiting Exoplanet Survey Satellite (TESS)
- discovery method
- Transit
- dist ly
- 431.6773
- eccentricity
- 0.023
- eq temp k
- 868
- insolation
- 132
- mass earth
- 27.4
- name
- TOI-1173 b
- orbital period days
- 7.0647
- radius earth
- 9.19
- sys num planets
- 1
How to see it
Like any astronomical target, TOI-1173 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 TOI-1173 b is an uncommon exoplanet
TOI-1173 b scores 25 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 8 points would lift it into a rarer tier.
That score comes from 4 science badges — Confirmed exoplanet, Gas giant, Puffy low-density world and Found by TESS — 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.