---
title: "Backyard Worlds"
chunk: 3/3
source: "https://en.wikipedia.org/wiki/Backyard_Worlds"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:13:25.266684+00:00"
instance: "kb-cron"
---

=== Co-moving benchmark systems ===
The backyard worlds project found additional co-moving systems. 34 low-mass co-moving companions were discovered in 2022 with the NOIRLab Source Catalog DR2. Later in March 2024 an additional 89 ultracool dwarf companions were identified. This study increased the number of ultracool companions to FGK stars by about 42%. These benchmark system represent a wide variety of systems, including six systems with white dwarf hosts, systems with binary hosts or companions that are binaries, systems with old or young ages, systems with red or blue spectral types and systems with a wide separation of >1000 astronomical units (AU). One young co-moving system consists of GJ 900, a K7+M4+M6 triple star system and the T9-dwarf CW2335+0142, which is a planetary-mass object (~10.5 MJ). Another notable system is CW0627−0028AB, which is a wide T0blue+T3 dwarf system or a possible triple (L5+T2.5)+T3 system. If the distance is confirmed, it would be the widest substellar binary discovered at a separation of about 860 AU. The brown dwarf companion CWISE J060202.17-462447.8 (~52 MJ) to the white dwarf WD J060159.98-462534.40 is an additional contender for the oldest brown dwarf with an age of 10.9+2.6−2.0 billion years. Additional M+T co-moving systems were discovered in April 2024 in a collaborative work together with the CatWISE team. 13 new systems were discovered, representing a 60% increase of the number of M+T systems. The sample includes young and old objects, including the candidate planetary-mass companion 2MASS J05581644–4501559 B and the brown dwarf UCAC3 52–1038 B, which is on a wide 7100 AU orbit. UCAC3 52–1038 B was later found to be a mildly metal-poor old brown dwarf. In December 2024 a team published a list of 51 ultracool dwarfs that are co-moving with white dwarfs. Some of these were also discovered by backyard worlds citizen scientists. In February 2025 follow-up observations of 10 candidate brown dwarfs orbiting white dwarfs were published. 7 turned out to be brown dwarf companions, one turned out to be a brown dwarf binary, one turned out to be the companion to a star and one was not confirmed due to blending in the spectrum.

=== Additional discoveries ===
This list contains additional notable discoveries by the Backyard Worlds: Planet 9 project.

== See also ==

Amateur astronomy
Citizen science
Zooniverse projects:

== References ==

== External links ==
Official website