Visibility I / V
(468861) 2013 LU28 (2013 LU28,2014 LJ9,2015 KB157) The Centaur / Damocloid was filmed on the second night of the February 2022 work. The centaur asteroid was discovered by the Mount Lemmon Survey on June 8, 2013 at Mount Lemmon Observatory (G96) at a magnitude of 21.7. Definition of Damocloid Wikipedia https://en.wikipedia.org/wiki/Damocloids . Definition of Centaur Wikipedia https://en.wikipedia.org/wiki/Kentauri_(little planet) . The definitions of the target asteroid are a bit contradictory, so the common definition fits well as the MPC has used it. The transneptune asteroid has a retrograde orbit (orbit opposite to the planets, orbital plane over 90 degrees) and an estimated size of about 110km. The orbit at a distance of 8.7-353.1au from the sun and the orbit of the sun around 2434 years. Source Wikipedia https://en.wikipedia.org/wiki/(468861)_2013_LU28 . At the time of imaging, the asteroid was 9.330942au away, with its nearest lap of 7.86au on January 5, 2025. This Centaur asteroid is the first we have intentionally described and methods are to be developed. Distant as well as dim objects require different methods. Now we only tried a short 3 image method that is going to continue later the next day! For this reason, we now report 3 measurements. A stack of 3 images measured as an addition, as objects are dimmed, this is probably a new method.
1Picture. first image in the series1 L120s measured, 2022-02-26UT 23: 47: 25UT 2459637.49126JDUT 12h23m13.99s + 59d00'40.2 "17.944mag Std Dev 97.352 SNR11.370 FWHM4.613", JPL Horizon 23: 47: 25UT 12h23m14.01s + 59d00'39.0 "18.688mag.
2Picture. last image in the series3 L120s measured, 2022-02-26UT 23: 51: 37UT 2459637.49417JDUT 12h23m13.91s + 59d00'40.9 "18.006mag Std Dev 96.224 SNR9.858 FWHM19.219", JPL Horizon 23: 51: 37UT 12h23m13.84s + 59d00'39.8 "18.688mag.
3Picture sum view of L120s 1-3 stack of images 23:49: 31.000 2459637.49271. 12h23m13.97s + 59d00'40.5 "18.296mag Std Dev 225.285 SNR25.551 FWHM3.506", JPL Horizon 23: 51: 37UT 12h23m13.93s + 59d00'39.4 "18.688mag.
No other asteroids below 24.0 mag are shown. TYC 3840-367-1 v. 11.15mag stars used to calibrate brightness measurement.