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ESO
@eso.org

That's no moon. It's a...hang on, what should we call it? 🤔 Our VLT has revealed evidence for a moon-like object in the CD-35 2722 system. Yet this new ‘exomoon’ detection is challenging cosmic labels! 🔭 🧪 #exoplanets 1/4

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ESO
@eso.org

Unlike moons in our Solar System, this object — a gaseous body at least as massive as Jupiter — does not orbit a planet. It circles a brown dwarf, that in turn orbits the CD-35 2722 star. Regardless of what to call this object, this discovery may mark an important first. 🔭 🧪 2/4

ESO
@eso.org

If confirmed, this could be the first ‘moon’ discovered outside our Solar System — something astronomers have been searching for years. This animation shows how the gravitational pull of the ‘moon’ makes the brown dwarf wobble, shifting its spectrum and so enabling the detection 👇 🔭 🧪 3/4

ESO
@eso.org

Read more: https://www.eso.org/public/news/eso2610/ 🔭 🧪 4/4

eso.orgNew ‘exomoon’ detection challenges cosmic labelsObservations made with the European Southern Observatory’s Very Large Telescope (ESO’s VLT) have revealed evidence for a moon-like object in the CD-35 2722 system. Unlike moons in our Solar System, the newly found object does not orbit a planet, raising questions about what to name it. Instead, it circles a brown dwarf, an object larger than a planet, that orbits the CD-35 2722 star. If confirmed, this could be the first ‘moon’ discovered outside our Solar System.
Jason Wright
@astrowright.bsky.social
Jason Wright@astrowright.bsky.social

On the contrary, this object is not just a moon, it is a moonmoon! Specifically, it is the moonmoon brown degenerate "star" CD-35 2722 Bb. The system is dynamically equivalent to the system in Figure 2 here: arxiv.org/abs/2303.18217

arxiv.orgA Unified Nomenclature and Taxonomy for Planets, Stars, and MoonsI solve the problem of nomenclature of planets, stars, and moons, and in doing so repair two of the IAU's blunders. Drawing and improving upon foundational work by Chen & Kipping, I describe a single,...