The COCONUTS-2 system in the bi-color AllWISE image (W1: green, W2: red). COCONUTS-2b stands out from the field with a very red W1−W2 color. These two objects are bound together and located ~35 light-years away, making COCONUTS-2b the closest directly imaged exoplanet ever, as of August 1, 2021. (NASA/WISE; Z. ZHANG ET AL. ARXIV:2107.02805)

Astronomers Go Nuts For Closest Exoplanet Directly Imaged Ever: COCONUTS-2b

At 35 light-years away, it’s also the 2nd coolest, 2nd widest planet ever found.

Despite discovering more than 4000 exoplanets, most remain obscure.

Although more than 4,000 confirmed exoplanets are known, with more than half of them uncovered by Kepler, directly imaging most of these exoplanets is not possible. Their small size and low luminosity, when coupled with the close separation distances from their parent stars, make that an impossibility. (NASA/AMES RESEARCH CENTER/JESSIE DOTSON AND WENDY STENZEL; MISSING EARTH-LIKE WORLDS BY E. SIEGEL)

Their nature — small, faint, and in tight orbits — prevent direct imaging.

An artist’s rendition of Proxima b orbiting Proxima Centauri. In order for direct imaging efforts to be successful, the planet must be well-enough separated from the parent star so that the parent star’s light can be blocked, but the reflected starlight from the planet will still be detected. (ESO/M. KORNMESSER)

The stellar glare simply overwhelms their planet’s reflected light.

Image of the exoplanet discovered in 2013, HD 95086 b. The star has been blocked out by a coronagraph and the diffraction patterns removed during data reduction. This detection showcases the present limits of exoplanet direct imaging, which require super-Jupiter masses and separation distances of many hundreds of AU from the parent star. (J. RAMEAU ET AL., ARXIV:1305.7428V1)

However, heat-generating exoplanets are special.

Three images of Jupiter show the gas giant in three different types of light — infrared, visible, and ultraviolet. The image on the left was taken in infrared by the Near-InfraRed Imager (NIRI) instrument at Gemini North in Hawaiʻi, the northern member of the international Gemini Observatory, a Program of NSF’s NOIRLab. The center image was taken in visible light by the Wide Field Camera 3 on the Hubble Space Telescope. The image on the right was taken in ultraviolet light by Hubble’s Wide Field Camera 3. All of the observations were taken on 11 January 2017. (INTERNATIONAL GEMINI OBSERVATORY/NOIRLAB/NSF/AURA/NASA/ESA, M.H. WONG AND I. DE PATER (UC BERKELEY) ET AL.)

Just like Jupiter, they reflect visible light, but emit their own infrared radiation.