Visibility III / V
980 The asteroid Anacostia (A921 WG, 1917 YC, 1921 W19) was imaged on the second night of the September 2021 work. The asteroid on the inner edge of the main zone was discovered by the American astronomer George Henry Peters on November 21, 1921 at the United States Naval Observatory (code 786) in Washington. The asteroid is named after the Washington DC district and especially its historic Nacochtank village area between the Anacostia River and the Patomac River, source Wikipedia https://en.wikipedia.org/wiki/Anacostia . The size of the asteroid is 74.67km and the rotation time is 20,117h / r.
Spectral class spec_T => SU and spec_B => L. As described, the asteroid was 1,311au at a distance and closest on September 28, 2021 to 1,259au.
We have photographed this object before in 2017 and Tapio Lahtinen has also photographed a light curve from it. The shooting took place in a cloud of clouds which meant that some of the images had to be removed.
1Picture. first image in the series1 L60s measured, 2021-09-04UT 21: 00: 17UT 2459462.37519JDUT 00h03m47.0s + 28d56'31.2 "11.003mag Std Dev 283.687 SNR47.735 FWHM3.017", JPL Horizon 21: 00: 17UT 00h03m47.02s + 28d56'30.1 "11.233 mag.
2Picture. last image in the series11 L60s measured, 2021-09-04UT 21: 11: 12UT 2459462.38277JDUT 00h03m46.66s + 28d56'33.3 "11.020mag Std Dev 331.311 SNR64139 FWHM3.817", JPL Horizon 21: 11: 12UT 00h03m46.68s + 28d56 ' 32.5 "11.233 mag.
3Picture sum view of L60s 1-7 from stack of pictures (11), motion not shown. No other asteroids under 19.5mag are shown. TYC 1735-826-1 v. 11.01mag stars used to calibrate brightness measurement.