Search for: All records

We report the discovery of cometary activity emanating from Main-belt asteroid 410590 (2008 GB₁₄₀), a finding facilitated, for the first time, by an artificial intelligence (AI) assistant. The assistant,TailNet, is a prototype we designed to enhance volunteer efforts of our Citizen Science projectActive Asteroids, a NASA Partner program hosted on theZooniverseplatform. Our follow-up investigation revealed eight Dark Energy Camera images showing 2008 GB₁₄₀with a tail spanning UT 2023 April 23–UT 2023 July 3, when the object was inbound to perihelion. We classify 2008 GB₁₄₀as an active asteroid and a candidate Main-belt comet (MBC)—a main-belt asteroid that undergoes volatile sublimation-driven activity. Notably, 2008 GB₁₄₀is presently near perihelion, thus the object is a prime target for follow-up observations to further characterize its activity.

We report the discovery of an active asteroid, 2016 UU₁₂₁, for the first time via artificial intelligence-enhanced classification, informed by our NASA Partner programActive Asteroids, a Citizen Science project hosted on theZooniverseplatform. The early version of our deep neural network,TailNet, identified potential activity associated with 2016 UU₁₂₁in 40 Dark Energy Camera (DECam) images from UT 2021 September 10 to 11. The discovery was vetted and confirmed by ourActive Asteroidscore science team. In total, 66 DECam images of this object showed clear activity in the form of a tail. 2016 UU₁₂₁has a Tisserand parameter with respect to Jupiter of 3.161, thus we classify the object as an active asteroid. Moreover, the activity occurred near perihelion, so 2016 UU₁₂₁is also a candidate Main-belt comet.

We present the Citizen Science program Active Asteroids and describe discoveries stemming from our ongoing project. Our NASA Partner program is hosted on the Zooniverse online platform and launched on 2021 August 31, with the goal of engaging the community in the search for active asteroids—asteroids with comet-like tails or comae. We also set out to identify other unusual active solar system objects, such as active Centaurs, active quasi-Hilda asteroids (QHAs), and Jupiter-family comets (JFCs). Active objects are rare in large part because they are difficult to identify, so we ask volunteers to assist us in searching for active bodies in our collection of millions of images of known minor planets. We produced these cutout images with our project pipeline that makes use of publicly available Dark Energy Camera data. Since the project launch, roughly 8300 volunteers have scrutinized some 430,000 images to great effect, which we describe in this work. In total, we have identified previously unknown activity on 15 asteroids, plus one Centaur, that were thought to be asteroidal (i.e., inactive). Of the asteroids, we classify four as active QHAs, seven as JFCs, and four as active asteroids, consisting of one main-belt comet (MBC) and three MBC candidates. We also include our findings concerning known active objects that our program facilitated, an unanticipated avenue of scientific discovery. These include discovering activity occurring during an orbital epoch for which objects were not known to be active, and the reclassification of objects based on our dynamical analyses.

We announce the discovery of cometary activity emitting from minor planet 2018 VL₁₀in Dark Energy Camera images spanning from UT 2018 December 31 to UT 2019 March 3. The activity was identified by volunteers of our NASA Partner programActive Asteroids, aZooniverse-hosted Citizen Science project designed to find previously unknown activity in known minor planets. Notably, 2018 VL₁₀crosses the orbits of Mars and Jupiter, and experiences close approaches of less than 0.5 au with both Earth and Jupiter. We classify 2018 VL₁₀as a member of the Jupiter-family comets, a group of objects especially important to understand because they hold important clues about the solar system volatile distribution, past and present.

We report our discovery of cometary activity in the form of a diffuse tail associated with minor planet 2008 QZ₄₄during two previous orbits: 2008 and 2017. This finding was prompted in part byActive Asteroids, ourZooniverse-hosted NASA Partner Citizen Science program. Participants flagged two UT 2017 July 12 Dark Energy Camera images of 2008 QZ₄₄as active. Independently, our team identified activity in nine Canada-France-Hawaii Telescope MegaPrime images from UT 2008 November 20. During both apparitions 2008 QZ₄₄was near its perihelion passage. 2008 QZ₄₄has a Tisserand parameter with respect to Jupiter of 2.821, placing it in the Jupiter-family comet (JFC) class, and our dynamical integrations confirm this classification. JFCs contain primordial material that informs us about solar system evolution, and help us map the present-day volatile distribution. We note that 2008 QZ₄₄has previously been classified as a quasi-Hilda comet candidate.

We have discovered evidence of cometary activity originating from (551023) 2012 UQ₁₉₂(alternately designated 2019 SN₄₀), which we dynamically classify as a Jupiter Family Comet (JFC). JFCs have eccentric Jupiter-crossing orbits and originate in the Kuiper Belt. Analysis of these objects can provide vital information about minor planets in the outer solar system, such as the distribution of volatiles within the solar system. Activity on 2012 UQ₁₉₂was first recognized by volunteers on our NASA Partner Citizen Science projectActive Asteroids. Through our own examination of archival image data, we found a total of ∼30 images presenting strong evidence of activity near perihelion during two separate orbits. 2012 UQ₁₉₂is notable as we found it to be recurrently active. When 2012 UQ₁₉₂approaches its perihelion passage in 2027 September, we predict it will reactivate and will be a prime subject for follow-up observations.

We present the DECam Ecliptic Exploration Project (DEEP) survey strategy, including observing cadence for orbit determination, exposure times, field pointings and filter choices. The overall goal of the survey is to discover and characterize the orbits of a few thousand Trans-Neptunian objects (TNOs) using the Dark Energy Camera (DECam) on the Cerro Tololo Inter-American Observatory Blanco 4 m telescope. The experiment is designed to collect a very deep series of exposures totaling a few hours on sky for each of several 2.7 square degree DECam fields-of-view to achieve approximate depths of magnitude 26.2 using a wideVRfilter that encompasses both theVandRbandpasses. In the first year, several nights were combined to achieve a sky area of about 34 square degrees. In subsequent years, the fields have been re-visited to allow TNOs to be tracked for orbit determination. When complete, DEEP will be the largest survey of the outer solar system ever undertaken in terms of newly discovered object numbers, and the most prolific at producing multiyear orbital information for the population of minor planets beyond Neptune at 30 au.

We report that minor planet 2004 CV₅₀displayed cometary activity in the form of a short, diffuse tail, first identified by volunteers of the Citizen Science programActive Asteroids, a NASA Partner program hosted on theZooniverseonline platform. The activity is present in three images, from UT 2020 February 15 and UT 2020 March 14, that were acquired with the Dark Energy Camera on the Blanco 4 m telescope at the Cerro-Tololo Inter-American Observatory in Chile. We find that 2004 CV₅₀is most likely an active quasi-Hilda object rather than an active asteroid, despite 2004 CV₅₀having a Tisserand parameter with respect to Jupiter of 3.06.

We present here the DECam Ecliptic Exploration Project (DEEP), a 3 yr NOAO/NOIRLab Survey that was allocated 46.5 nights to discover and measure the properties of thousands of trans-Neptunian objects (TNOs) to magnitudes as faint as VR ∼ 27 mag, corresponding to sizes as small as 20 km diameter. In this paper we present the science goals of this project, the experimental design of our survey, and a technical demonstration of our approach. The core of our project is “digital tracking,” in which all collected images are combined at a range of motion vectors to detect unknown TNOs that are fainter than the single exposure depth of VR ∼ 23 mag. Through this approach, we reach a depth that is approximately 2.5 mag fainter than the standard LSST “wide fast deep” nominal survey depth of 24.5 mag. DEEP will more than double the number of known TNOs with observational arcs of 24 hr or more, and increase by a factor of 10 or more the number of known small (<50 km) TNOs. We also describe our ancillary science goals, including measuring the mean shape distribution of very small main-belt asteroids, and briefly outline a set of forthcoming papers that present further aspects of and preliminary results from the DEEP program.

We present the methods and results from the discovery and photometric measurement of 26 bright VR > 24 trans-Neptunian objects (TNOs) during the first year (2019–20) of the DECam Ecliptic Exploration Project (DEEP). The DEEP survey is an observational TNO survey with wide sky coverage, high sensitivity, and a fast photometric cadence. We apply a computer vision technique known as a progressive probabilistic Hough transform to identify linearly moving transient sources within DEEP photometric catalogs. After subsequent visual vetting, we provide a photometric and astrometric catalog of our TNOs. By modeling the partial lightcurve amplitude distribution of the DEEP TNOs using Monte Carlo techniques, we find our data to be most consistent with an average TNO axis ratiob/a< 0.5, implying a population dominated by non-spherical objects. Based on ellipsoidal gravitational stability arguments, we find our data to be consistent with a TNO population containing a high fraction of contact binaries or other extremely non-spherical objects. We also discuss our data as evidence that the expected binarity fraction of TNOs may be size-dependent.