Observation by Simon Kidd: New moon discovered orbiting Asteroid

Uploaded by

Simon Kidd

Observer

Simon Kidd

Observed

2025 Dec 03 - 00:24

Uploaded

2026 May 13 - 09:23

Objects

50142 2000 AY129

Equipment

Celestron C14, 0.6 reducer, ZWO ASI432 camera

Exposure

0.044s, (SER 23fps)

Location

Hertfordshire, UK

Target name

Asteroid (50142) 2000 AY129

Title

New moon discovered orbiting Asteroid

About this image

Discovery plot of the light from star UCAC4 541-014802, being occulted by asteroid (50142) 2000 AY129, 03/12/25 at 0024:42

The green trace represents a nearby reference star. Conditions were good.

The double dip ultimately confirmed the presence of a previously unknown moon orbiting the asteroid.

Here is the link to the discovery 'Telegram' issued by CBET at Harvard. This contains a description of the analysis.

http://www.cbat.eps.harvard.edu/iau/cbet/005600/CBET005656.txt

This is the 19th (I think) asteroid satellite to be discovered by occultation, and may be the first from UK soil.

Thanks to the BAA team (T. Haymes, A. Pratt) also C.Weber, D.Gault and D.Herald (IOTA)

Files associated with this observation

2025-12-03-0024_8-2000 AY129 7ms AD.png (36.6 kB)

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