Visibility II / V
4544 Xanthus (1989 FB) The asteroid Apollo NEO / PHA was photographed on the first night of March 2022. The asteroid was discovered at the Palomar Observatory (675 Palomar Mountain) by American astronomers Henry E. Holt and Norman Gene Thomas (1930-2020) on March 31, 1989. In the 1960s, planetary geologist Henry Holt studied the photometric properties of the lunar surface as part of the Surveyor and Apollo programs. Source Wikipedia https://en.wikipedia.org/wiki/Henry_E._Holt . Holt has found a total of 689 asteroids and comets 121P / Shoemaker-Holt, 127P / Holt-Olmstead, and 128P / Shoemaker-Holt. Norman Thomas has been at the Lowel Observatory as a planet seeker, e.g. together with Robert Burnham, Jr.. Thomas has found a total of 55 asteroids. Source Wikipedia https://en.wikipedia.org/wiki/Norman_G._Thomas . The asteroid of the name is the basis for naming: This is another Greek name for Apollo, meaning "mass"; as such, Xanthus rejoiced in high places such as the peaks of the high mountains and the ripples of the sea. [Reference: Minor Planet Circ.18459]. An explanation of the name in Greek mythology refers to the second horse of Achilles, Xanthus. Source Wikipedia https://en.wikipedia.org/wiki/Balius_and_Xanthus . The size of the asteroid is 1.3km and the rotation speed is 37.65h / r. When photographed, the asteroid was 0.35050au away, the closest it is 0.22366au on May 1, 2022. Due to a change in weather, the last image is a stack.
1Picture. stacked 1-11 images L120s sum of the stars, motion is shown. Asteroid (83631) 2001 SH317 19.30mag, motion shown. No other asteroids under 19.4 mag are shown.
2Picture. first picture measured, 2022-03-26T 01: 29: 08UT 2459664.56189JDUT 14h59m45.97s -08d28'39.6 "17.07mag Std Dev 98.009 SNR19.011 FWHM6.517", JPL Horizon 01: 29: 08UT 14h59m45.97s -08d28 ' 39.1 "16.788 mag.
3Picture. last image, stack of images 10-11 measured, 2022-03-26UT 01: 47: 57UT 2459664.57496JDUT 14h59m44.81s -08d28'55.0 "17.403mag Std Dev 82.202 SNR9.351 FWHM5.64", JPL Horizon 01: 47: 57UT 14h59m44.89s -08d28'53.7 "16.788mag.
TYC 5579-30-1 v.12.15mag stars used to calibrate the brightness measurement.