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We report the discovery of WISE2150-7520AB (W2150AB): a widely separated (~ 341 AU) very low mass L1 + T8 co-moving system. The system consists of the previously known L1 primary 2MASS J21501592-7520367 and a newly discovered T8 secondary found at position 21:50:18.99 -75:20:54.6 (MJD=57947) using Wide-field Infrared Survey Explorer (WISE) data via the Backyard Worlds: Planet 9 citizen science project. We present Spitzer ch1 and ch2 photometry (ch1-ch2= 1.41 +/-0.04 mag) of the secondary and FIRE prism spectra of both components. The sources show no peculiar spectral or photometric signatures indicating that each component is likely field age. Using all observed data and the Gaia DR2 parallax of 41.3593 +/- 0.2799 mas for W2150A we deduce fundamental parameters of log(Lbol/Lsun)=-3.69 +/- 0.01, Teff=2118 +/- 62 K, and an estimated mass=72 +/- 12 MJup for the L1 and log(Lbol/Lsun)=-5.64 +/- 0.02, Teff=719 +/- 61 K, and an estimated mass=34 +/- 22 MJup for the T8. At a physical separation of ~341 AU this system has Ebin = 10^41 erg making it the lowest binding energy system of any pair with Mtot < 0.1 Msun not associated with a young cluster. It is equivalent in estimated mass ratio, Ebin, and physical separation to the ~ 2 Myr M7.25 + M8.25 binary brown dwarf 2MASS J11011926-7732383AB (2M1101AB) found in the Chameleon star forming region. W2150AB is the widest companion system yet observed in the field where the primary is an L dwarf or later.

We present the discovery of 13 new widely separated T dwarf companions to M dwarf primaries, identified using WISE/NEOWISE data by the CatWISE and Backyard Worlds: Planet 9 projects. This sample represents a \\(\\sim\\)60% increase in the number of known M+T systems, and allows us to probe the most extreme products of binary/planetary system formation, a discovery space made available by the CatWISE2020 catalog and the Backyard Worlds: Planet 9 effort. Highlights among the sample are WISEP J075108.79-763449.6, a previously known T9 thought to be old due to its SED, which we now find is part of a common-proper-motion pair with L 34-26 A, a well studied young M3 V star within 10 pc of the Sun; CWISE J054129.32-745021.5 B and 2MASS J05581644-4501559 B, two T8 dwarfs possibly associated with the very fast-rotating M4 V stars CWISE J054129.32-745021.5 A and 2MASS J05581644-4501559 A; and UCAC3 52-1038 B, which is among the widest late T companions to main sequence stars, with a projected separation of \\(\\sim\\)7100 au. The new benchmarks presented here are prime \\(JWST\\) targets, and can help us place strong constraints on formation and evolution theory of substellar objects as well as on atmospheric models for these cold exoplanet analogs.

We introduce the Wide-field Retrieval of Astrodata Program (WRAP), a tool created to aid astronomers in gathering photometric and astrometric data for point sources that may confuse simple cross-matching algorithms because of their faintness or motion. WRAP allows astronomers to correctly cross-identify objects with proper motion across multiple surveys by wedding the catalog data with its underlying images, thus providing visual confirmation of cross-associations in real time. Developed within the Backyard Worlds: Planet 9 citizen science project, WRAP aims to aid in the characterization of faint, high motion sources by this collaboration (and others).

We present the discovery of CWISE J151044.74\\(-\\)524923.5, a wide low-mass companion to the nearby (\\(\\sim\\)24.7 pc) system L 262-74, which was identified through the Backyard Worlds: Planet 9 citizen science project. We detail the properties of the system, and we assess that this companion is a mid-L dwarf, which will need to be verified spectroscopically. With an angular separation of 74\\farcs3, we estimate a projected physical separation of \\(\\sim\\)1837 au from the central system.

We present the discovery of CWISE J052306.42\\(-\\)015355.4, which was found as a faint, significant proper motion object (0.52 \\(\\pm\\) 0.08 arcsec yr\\(^{-1}\\)) using machine learning tools on the unWISE re-processing on time series images from the Wide-field Infrared Survey Explorer. Using the CatWISE2020 W1 and W2 magnitudes along with a \\(J-\\)band detection from the VISTA Hemisphere Survey, the location of CWISE J052306.42\\(-\\)015355.4 on the W1\\(-\\)W2 vs. \\(J-\\)W2 diagram best matches that of other known, or suspected, extreme T subdwarfs. As there is currently very little knowledge concerning extreme T subdwarfs we estimate a rough distance of \\(\\le\\) 68 pc, which results in a tangential velocity of \\(\\le\\) 167 km s\\(^{-1}\\), both of which are tentative. A measured parallax is greatly needed to test these values. We also estimate a metallicity of \\(-1.5 <\\) [M/H] \\(< -0.5\\) using theoretical predictions.

We present the discovery of a low-mass comoving system found by means of the NOIRLab Source Catalog (NSC) DR2. The system consists of the high proper-motion star LEHPM 5005 and an ultracool companion 2MASS J22410186-4500298 with an estimated spectral type of L2. The primary (LEHPM 5005) is likely a mid-M dwarf but over-luminous for its color, indicating a possible close equal mass binary. According to the Gaia EDR3 parallax of the primary, the system is located at a distance of \\(58\\pm2\\) pc. We calculated an angular separation of 7.2\" between both components, resulting in a projected physical separation of 418 AU.

We present the discovery of 34 comoving systems containing an ultra-cool dwarf found by means of the NOIRLab Source Catalog (NSC) DR2. NSC's angular resolution of \\(\\sim\\)1\" allows for the detection of small separation binaries with significant proper motions. We used the catalog's accurate proper motion measurements to identify the companions by cross-matching a previously compiled list of brown dwarf candidates with NSC DR2. The comoving pairs consist of either a very low-mass star and an ultra-cool companion, or a white dwarf and an ultra-cool companion. The estimated spectral types of the primaries are in the K and M dwarf regimes, those of the secondaries in the M, L and T dwarf regimes. We calculated angular separations between \\(\\sim\\)2 and \\(\\sim\\)56\", parallactic distances between \\(\\sim\\)43 and \\(\\sim\\)261 pc and projected physical separations between \\(\\sim\\)169 and \\(\\sim\\)8487 AU. The lowest measured total proper motion is 97 mas yr\\(^{-1}\\), the highest 314 mas yr\\(^{-1}\\). Tangential velocities range from \\(\\sim\\)23 to \\(\\sim\\)187 km s\\(^{-1}\\). We also determined comoving probabilities, estimated mass ratios and calculated binding energies for each system. We found no indication of possible binarity for any component of the 34 systems in the published literature. The discovered systems can contribute to the further study of the formation and evolution of low-mass systems as well as to the characterization of cool substellar objects.

While stars are often found in binary systems, brown dwarf binaries are much rarer. Brown dwarf--brown dwarf pairs are typically difficult to resolve because they often have very small separations. Using brown dwarfs discovered with data from the Wide-field Infrared Survey Explorer (WISE) via the Backyard Worlds: Planet 9 citizen science project, we inspected other, higher resolution, sky surveys for overlooked cold companions. During this process we discovered the brown dwarf binary system CWISE J0146\\(-\\)0508AB, which we find has a very small chance alignment probability based on the similar proper motions of the components of the system. Using follow-up near-infrared spectroscopy with Keck/NIRES, we determined component spectral types of L4 and L8 (blue), making CWISE J0146\\(-\\)0508AB one of only a few benchmark systems with a blue L dwarf. At an estimated distance of \\(\\sim\\)40 pc, CWISE J0146\\(-\\)0508AB has a projected separation of \\(\\sim\\)129 AU, making it the widest separation brown dwarf pair found to date. We find that such a wide separation for a brown dwarf binary may imply formation in a low-density star-forming region.

We present the discovery of CWISE J050626.96\\(+\\)073842.4 (CWISE J0506\\(+\\)0738), an L/T transition dwarf with extremely red near-infrared colors discovered through the Backyard Worlds: Planet 9 citizen science project. Photometry from UKIRT and CatWISE give a \\((J-K)_{\\rm MKO}\\) color of 2.97\\(\\pm\\)0.03 mag and a \\(J_{\\rm MKO}-\\)W2 color of 4.93\\(\\pm\\)0.02 mag, making CWISE J0506\\(+\\)0738 the reddest known free-floating L/T dwarf in both colors. We confirm the extremely red nature of CWISE J0506\\(+\\)0738 using Keck/NIRES near-infrared spectroscopy and establish that it is a low-gravity late-type L/T transition dwarf. The spectrum of CWISE J0506\\(+\\)0738 shows possible signatures of CH\\(_4\\) absorption in its atmosphere, suggesting a colder effective temperature than other known, young, red L dwarfs. We assign a preliminary spectral type for this source of L8\\(\\gamma\\)-T0\\(\\gamma\\). We tentatively find that CWISE J0506\\(+\\)0738 is variable at 3-5 \\(\\mu\\)m based on multi-epoch WISE photometry. Proper motions derived from follow-up UKIRT observations combined with a radial velocity from our Keck/NIRES spectrum and a photometric distance estimate indicate a strong membership probability in the \\(\\beta\\) Pic moving group. A future parallax measurement will help to establish a more definitive moving group membership for this unusual object.

In an effort to identify nearby and unusual cold objects in the solar neighborhood, we searched for previously unidentified moving objects using CatWISE2020 proper motion data combined with machine learning methods. We paired the motion candidates with their counterparts in 2MASS, UHS, and VHS. Then we searched for white dwarf, brown dwarf, and subdwarf outliers on the resulting color-color diagrams. This resulted in the discovery of 16 new dwarfs including two nearby M dwarfs (< 30 pc), a possible young L dwarf, a high motion early T dwarf and 3 later T dwarfs. This research represents a step forward in completing the census of the Sun's neighbors.