Suresh, AswinKarambelkar, VirajKasliwal, Mansi M.Ashley, Michael C.B.De, KishalayHankins, Matthew J.Moore, Anna M.Soon, JamieSoria, RobertoTravouillon, TonyTruong, Kayton K.2025-05-232025-05-230004-6280ORCID:/0000-0001-9304-6718/work/184099707ORCID:/0000-0002-2894-6936/work/184104552http://www.scopus.com/inward/record.url?scp=85201766478&partnerID=8YFLogxKhttps://hdl.handle.net/1885/733752862Long Period Variables (LPVs) are stars with periods of several hundred days, representing the late, dust-enshrouded phase of stellar evolution in low to intermediate mass stars. In this paper, we present a catalog of 154,755 LPVs using near-IR lightcurves from the Palomar Gattini-IR (PGIR) survey. PGIR has been surveying the entire accessible northern sky (δ > −28°) in the J-band at a cadence of 2-3 days since 2018 September, and has produced J-band lightcurves for more than 60 million sources. We used a gradient-boosted decision tree classifier trained on a comprehensive feature set extracted from PGIR lightcurves to search for LPVs in this data set. We developed a parallelized and optimized code to extract features at a rate of ∼0.1 s per lightcurve. Our model can successfully distinguish LPVs from other stars with a true positive rate of 95%. Cross-matching with known LPVs, we find 70,369 (∼46%) new LPVs in our catalog.We thank the referee for useful suggestions that helped improve this manuscript. Palomar Gattini-IR (PGIR) is generously funded by Caltech, Australian National University, the Mt Cuba Foundation, the Heising Simons Foundation, the Binational Science Foundation. PGIR is a collaborative project among Caltech, Australian National University, University of New South Wales, Columbia University and the Weizmann Institute of Science. M.M.K. acknowledges generous support from the David and Lucille Packard Foundation. M.M.K. acknowledges the US-Israel Bi-national Science Foundation grant 2016227. M.M.K. acknowledges the Heising-Simons foundation for support via a Scialog fellowship of the Research Corporation. M.M.K. and A.M.M. acknowledge the Mt Cuba foundation. J.S. is supported by an Australian Government Research Training Program (RTP) Scholarship. A.S. acknowledges support from the Caltech Summer Undergraduate Research Fellowship (SURF) funded by the NSF Astronomy and Astrophysics grant No. 2206730. K.D. was supported by NASA through the NASA Hubble Fellowship grant #HST-HF2-51477.001 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. R.S. acknowledges grant No. 12073029 from the National Natural Science Foundation of China (NSFC).en© 2024. The Author(s). Published by IOP Publishing Ltd on behalf of the Astronomical Society of the Pacific (ASP).2024-08-2010.1088/1538-3873/ad68a485201766478