(768325) 2015 BP519

Extreme trans-Neptunian object 2015 BP 513, an Apollo asteroid October 2018 yes #C2E0FF (768325) 2015 BP 519 Planet nine-etnos now-new3.png Orbital diagram of 2015 BP 519 and other extreme objects along with hypothetical Planet Nine Dark Energy Survey Cerro Tololo Obs. 17 January 2015(first observed only) (768325) 2015 BP 519 "Caju" (nickname)PowerPoint-Caju TNOESDOETNOdistant 27 April 2019 (JD 2458600.5) 5 3.22 yr (1,176 d) 820 AU 35.2 AU ≈ 7 September 2058JPL Horizons Observer Location: @sun (Perihelion occurs when deldot changes from negative to positive. Uncertainty in time of perihelion is 3-sigma.)±1 month 428.03 AU 0.9178 8856 yr (3,234,488 d) 358.39° 0.0001 ms / day 54.125° 135.11° 348.37° 0 524 km (est.)516 km (est.)400 - 700 km (est.)719 309 208 km (from assumed albedo) 0.08 (assumed)0.124 (assumed) 0.07 to 0.21 (assumed) g–r 0.79 0.17r–i 0.19 0.12r–z 0.42 0.15i–z 0.23 0.15 21.5 4.32 (768325) 2015 BP 519, internally nicknamed Caju,PowerPoint-Caju is an extreme trans-Neptunian object from the scattered disc on a highly eccentric and inclined orbit in the outermost region of the Solar System. It has been described as an extended scattered disc object (ESDO), and fits into the group of extreme objects that led to the prediction of Planet Nine, and has the highest orbital inclination of any of these objects.PowerPoint-Caju The diameter of 2015 BP 519 is estimated to be 719 309 208 km. History Discovery and observations thumb|The 4.0-meter Víctor M. Blanco Telescope at Cerro Tololo Observatory, which houses the Dark Energy Camera (DECam) 2015 BP 519 was first observed on 17 January 2015, by astronomers with the Dark Energy Survey at Cerro Tololo Observatory W84 in Chile. The body's observation arc begins with a precovery taken on 27 November 2014 by astronomers with the Dark Energy Survey using the DECam instrument of the Víctor M. Blanco Telescope at Cerro Tololo Inter-American Observatory in Chile. Its discovery was reported in a paper published by Dark Energy Survey astronomers in 2018. Naming As of 2026, 2015 BP 519 has not been named, but it is nicknamed Caju ("cashew") by the discovery team.PowerPoint-Caju Orbit and classification thumb|upright=2|This image shows the plot of eccentricity and perihelion of trans-Neptunian objects, colored by their main dynamical categories. 2015 BP 519 is shown at the top, left of 2017 OF 201. Orbital characteristics 2015 BP 519 orbits the Sun at a distance of 35.2–821 AU once every 8856 years (3,234,488 days; semi-major axis of 428 AU). Its orbit has an exceptionally high eccentricity of 0.92 and an inclination of 54° with respect to the ecliptic. This makes it a probable outlier among the known extreme trans-Neptunian objects. It has been described as an extended scattered disc object (ESDO). Planet Nine hypothesis 2015 BP 519 fits into the group of extreme trans-Neptunian objects that originally led to the prediction of Planet Nine.PowerPoint-Caju13 The group consists of more than a dozen bodies with a perihelion greater than 30 AU and a semi-major axis greater than 250 AU, with 2015 BP 519 having the highest orbital inclination of any of these objects.PowerPoint-Caju Subsequently, unrefereed work by de la Fuente Marcos (2018) found that 2015 BP 519 current orbital orientation in space is not easily explained by the same mechanism that keeps other extreme trans-Neptunian objects together, suggesting that the clustering in its orbital angles cannot be attributed to Planet Nine's influence. However, regardless of the current direction of its orbit, its high orbital inclination appears to fit into the class of high-semi major axis, high-inclination objects predicted by Batygin & Morbedelli (2017) to be generated by Planet Nine. Physical characteristics Size and albedo According to the original paper for the discovery of the object, its diameter is estimated to be 400 km to 700 km, using a albedo of 0.07 to 0.21. However, according to Michael Brown and Johnston's Archive, 2015 BP 519 measures 524 and 516 kilometers in diameter based on an assumed albedo of 0.08 and 0.124, respectively. A newer 2025 study estimated its diameter at 719 309 208 km assuming a median geometric albedo, which is bigger than previously thought. Spectra and surface 2015 BP 519 has color indices of: g-r 0.79 ± 0.17, r-i 0.19 ± 0.12, r-z 0.42 ± 0.15 and i-z 0.23 ± 0.15. The color of 2015 BP 519 is moderately red. Upcoming observations As of 2018, no rotational lightcurve of has been obtained from photometric observations. The body's rotation period, pole and shape remain unknown. It has not yet been imaged by high-resolution telescopes, so it has no known moons. The Hubble Space Telescope is planned to image 2015 BP 519 in 2026, which should determine if it has significantly sized moons. See also Sedna Notes PowerPoint-Caju The nickname "Caju" is mentioned in the downloadable PowerPoint presentation "Evaluating the Dynamical Stability of Outer Solar System Objects in the Presence of Planet Nine", by Juliette Becker, Fred Adams, Tali Khain, Stephanie Hamilton, and David Gerdes at University of Michigan. References 30em 2018-02-15 last obs. JPL Small-Body Database Browser: (2015 BP519) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3823898 Jet Propulsion Laboratory 10 May 2018 2015 BP519 Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=2015+BP519 10 May 2018 List Of Centaurs and Scattered-Disk Objects Minor Planet Center https://www.minorplanetcenter.net/iau/lists/t_centaurs.html 9 February 2018 List of Known Trans-Neptunian Objects Johnston's Archive 7 October 2018 http://www.johnstonsarchive.net/astro/tnoslist.html 23 October 2018 How many dwarf planets are there in the outer solar system? California Institute of Technology Brown Michael E. http://web.gps.caltech.edu/~mbrown/dps.html 23 October 2018 6 J. C. Becker T. Khain S. J. Hamilton F. C. Adams D. W. Gerdes L. Zullo K. Franson S. Millholland G. M. Bernstein M. Sako P. Bernardinelli K. Napier L. Markwardt Hsing Wen Lin W. Wester F. B. Abdalla S. Allam J. Annis S. Avila E. Bertin D. Brooks A. Carnero Rosell M. Carrasco Kind J. Carretero C. E. Cunha C. B. D'Andrea L. N. da Costa C. Davis J. De Vicente H. T. Diehl P. Doel T. F. Eifler B. Flaugher P. Fosalba J. Frieman J. García-Bellido E. Gaztanaga D. Gruen R. A. Gruendl J. Gschwend G. Gutierrez W. G. Hartley D. L. Hollowood K. Honscheid D. J. James K. Kuehn N. Kuropatkin M. A. G. Maia M. March J. L. Marshall F. Menanteau R. Miquel R. L. C. Ogando A. A. Plazas E. Sanchez V. Scarpine R. Schindler I. Sevilla-Noarbe M. Smith R. C. Smith M. Soares-Santos F. Sobreira E. Suchyta M. E. C. Swanson A. R. Walker DES Collaboration August 2018 Discovery and Dynamical Analysis of an Extreme Trans-Neptunian Object with a High Orbital Inclination The Astronomical Journal 156 2 17 2018AJ....156...81B 10.3847/1538-3881/aad042 1805.05355 55163842 free Carlos de la Fuente Marcos Raúl de la Fuente Marcos September 2018 A Fruit of a Different Kind: 2015 BP519 as an Outlier Among the Extreme Trans-neptunian Objects Research Notes of the American Astronomical Society 2 3 167 2018RNAAS...2c.167D 10.3847/2515-5172/aadfec 1809.02571 119433944 free A Search For The Moons of Mid-Sized TNOs https://www.stsci.edu/hst-program-info/download/hst/pdf/18010/ Benjamin Proudfoot Mikulski Archive for Space Telescopes Space Telescope Science Institute August 2025 HST Proposal 18010 Cycle 33 2025-08-17 Ferreira Feliphe S. Camargo Julio I. B. Boufleur Rodrigo Banda-Huarca M. V. Pieres Adriano Peixoto Viviane F. Assafin Marcelo Bernardinelli P. H. Lin H. W. Braga-Ribas Felipe Gomes-Junior Altair Vieira-Martins Roberto Costa da Abbott T. M. C. Aguena M. Allam Sahar S. Alves O. Annis J. Bacon D. Brooks D. Burke D. L. Rosell A. Carneiro Carretero J. Desai S. Doel P. Everett S. Ferrero I. Frieman J. García-Bellido J. Gatti M. Gaztanaga E. Giannini G. Gruen D. Gruendl R. A. Herner K. Hinton S. R. Hollowood D. L. Honscheid K. James D. J. Kuehn K. Lee S. Marshall J. L. Mena-Fernández J. Miquel R. Myles J. Palmese A. Malagón A. A. Plazas Pereira M. E. S. Samuroff S. Sanchez E. Cid D. Sanchez Servila-Noarbe I. Smith M. Suchyta E. Swanson M. E. C. Tarle G. To C. Tucker D. L. Vicente de Vikram V. Walker A. R. Weaverdyck N. Collaboration DES Year six photometric measurements of known Trans-Neptunian Objects and Centaurs by the Dark Energy Survey arXiv.org 2025-04-23 https://arxiv.org/abs/2504.16927 2026-10-08 External links Discovery and Dynamical Analysis of an Extreme Trans-Neptunian Object with a High Orbital Inclination, 14 May 2018 A New World's Extraordinary Orbit Points to Planet Nine 15 May 2018 2015BP519 3823898 768325 (768325) 2015 BP 519 Category:Scattered disc and detached objects Category:Extreme trans-Neptunian objects Category:Discoveries by OSSOS 20151127 Category:Inner Oort cloud