Trans-Neptunian Objects Found in the First Four Years of the Dark Energy Survey

Abstract

We present a catalog of 316 trans-Neptunian bodies detected by the Dark Energy Survey (DES ). These objects include 245 discoveries by DES (139 not previously published) detected in ≈ 60, 000 exposures from the first four seasons of the survey ("Y4" data). The survey covers a contiguous 5000 deg 2 of the southern sky in the grizY optical/NIR filter set, with a typical TNO in this part of the sky being targeted by 25 − 30 Y4 exposures. We describe the processes for detection of transient sources and the linkage into TNO orbits, which are made challenging by the absence of the fewhour repeat observations employed by TNO-optimized surveys. We also describe the procedures for determining detection efficiencies vs. magnitude and estimating rates of false-positive linkages. This work presents all TNOs which were detected on ≥ 6 unique nights in the Y4 data and pass a "subthreshold confirmation" test wherein we demand the the object be detectable in a stack of the individual images in which the orbit indicates an object should be present, but was not detected. This eliminates false positives and yields TNO detections complete to r 23.3 mag with virtually no dependence on orbital properties for bound TNOs at distance 30 AU < d < 2500 AU. The final DES TNO catalog is expected to yield > 0.3 mag more depth, and arcs of > 4 years for nearly all detections.

OSSOS. XVII. An upper limit on the number of distant planetary objects in the Solar System

“…Because the H-magnitude distribution is shallow, usage of large apertures is not as important as sky coverage; the sum of existing wide-field surveys (eg. Sheppard and Trujillo [21], Bernardinelli et al [4]), some of which is far from the ecliptic, provides an even smaller chance of success than LSST of finding such a distant planet.…”

Enhancing Ground-Based Observations of Trans-Neptunian Objects using a Single-Epoch Parallax Measurement from L2

“…(2) The associated astrometric uncertainties σ are specific to the instrumental precision of the observing program, and are assumed to be circular. Since a single observation from L2 affords us an excellent estimate on the distance, we include an additional contribution to our chi-squared function (a prior on distance), similar to Bernardinelli et al (2020),…”

“…Figure 1 shows the distributions of absolute magnitude H (defined as the visual magnitude a TNO would have if it were placed 1 au from both the Sun and Earth) versus current distance from the Sun at the time of this publication for known TNOs, and shows that most objects reported by the MPC can easily be observed within five minutes of integration on Subaru using the HSC. While recent largescale surveys for TNOs report a steep drop in detection efficiency beyond R ∼23-24 (Petit et al 2011;Bannister et al 2016Bannister et al , 2018Bernardinelli et al 2020;Bernardinelli et al 2021), a signal-to-noise ratio of S/N = 25 could be achieved from the ground on TNOs of R ∼24 with the HSC using only ∼400 s of integration according to the Subaru HSC's Exposure Time Calculator 2 assuming preset observing conditions. Though dozens of TNOs have already been found at fainter magnitudes than this threshold, these objects are typically discovered via more focused pencil-beam or shift-and-stack surveys (Gladman et al 1998;Bernstein et al 2004;Fraser & Kavelaars 2008;Fuentes et al 2009;Parker & Kavelaars 2010).…”

“…Some 15 yr later, Becker et al (2018) published the discovery a new object, 2015 BP 519 , which has an extreme orbit (a ∼ 450 au, e ∼ 0.92) similar to that of Sedna and determined an orbital solution with 27 observations over a timespan of 1110 days. All surveys that search for TNOs (see, for example, Jewitt & Luu 1993, 1995Luu et al 1997;Brown & Webster 1998;Gladman et al 1998;Trujillo et al 2000;Allen et al 2001;Bernstein et al 2004;Elliot et al 2005;Fraser & Kavelaars 2008;Fuentes & Holman 2008;Fuentes et al 2009;Parker & Kavelaars 2010;Schwamb et al 2010;Petit et al 2011;Petit et al 2017;Alexandersen et al 2016;Bannister et al 2016Bannister et al , 2018Weryk et al 2016;Whidden et al 2019;Bernardinelli et al 2020;Bernardinelli et al 2021), have the same requirement that many observations of an object across multiple oppositions are needed in order to constrain its orbit. Requiring multiple oppositions' worth of data runs the risk of losing the object on the sky before properly measuring its orbit.…”

“…Even larger-scale projects, which hunt for and return hundreds of classical belt (closer-in, more circular) objects, require many observations spanning multiple years. Among the most notable of such missions in recent history are the Dark Energy Survey (DES, The Dark Energy Survey Collaboration 2005; Bernardinelli et al 2020;Bernardinelli et al 2021), the Canada-France Ecliptic Plane Survey (CFEPS, Petit et al 2011;Petit et al 2017), and the Outer Solar Systems Origin Survey (OS-SOS, Bannister et al 2016Bannister et al , 2018. Respectively, DES, CFEPS, and OSSOS have published the orbits of 817, 169, and 838 outer solar system objects; each mission required multiple oppositions and many observational epochs to achieve a reliable level of precision in the orbit determinations.…”