|| March 13, 2007 || Kitt Peak || Spacewatch || (159) || align=right | 2.6 km || |-id=276 bgcolor=#d6d6d6 | 401276 || || — || May 8, 2008 || Mount Lemmon || Mount Lemmon Survey || — || align=right | 3.4 km || |-id=277 bgcolor=#d6d6d6 | 401277 || || — || September 8, 2004 || Socorro || LINEAR || — || align=right | 4.2 km || |-id=278 bgcolor=#E9E9E9 | 401278 || || — || February 8, 2008 || Kitt Peak || Spacewatch || — || align=right | 1.6 km || |-id=279 bgcolor=#d6d6d6 | 401279 || || — || July 3, 2003 || Kitt Peak || Spacewatch || — || align=right | 3.9 km || |-id=280 bgcolor=#d6d6d6 | 401280 || || — || November 22, 2005 || Catalina || CSS || — || align=right | 3.2 km || |-id=281 bgcolor=#d6d6d6 | 401281 || || — || December 27, 2005 || Kitt Peak || Spacewatch || — || align=right | 4.1 km || |-id=282 bgcolor=#d6d6d6 | 401282 || || — || April 30, 2008 || Mount Lemmon || Mount Lemmon Survey || EOS || align=right | 2.0 km || |-id=283 bgcolor=#d6d6d6 | 401283 || || — || November 28, 2005 || Kitt Peak || Spacewatch || EOS || align=right | 2.2 km || |-id=284 bgcolor=#d6d6d6 | 401284 || || — || November 7, 2010 || Mount Lemmon || Mount Lemmon Survey || — || align=right | 3.9 km || |-id=285 bgcolor=#d6d6d6 | 401285 || || — || August 3, 2008 || Siding Spring || SSS || — || align=right | 4.2 km || |-id=286 bgcolor=#d6d6d6 | 401286 || || — || August 27, 2009 || Kitt Peak || Spacewatch || — || align=right | 3.7 km || |-id=287 bgcolor=#d6d6d6 | 401287 || || — || September 30, 2005 || Mount Lemmon || Mount Lemmon Survey || — || align=right | 3.9 km || |-id=288 bgcolor=#d6d6d6 | 401288 || || — || February 16, 2001 || Kitt Peak || Spacewatch || — || align=right | 3.6 km || |-id=289 bgcolor=#d6d6d6 | 401289 || || — || September 13, 2005 || Catalina || CSS || BRA || align=right | 1.9 km || |-id=290 bgcolor=#E9E9E9 | 401290 || || — || October 26, 2005 || Kitt Peak || Spacewatch || AGN || align=right | 1.7 km || |-id=291 bgcolor=#E9E9E9 | 401291 || || — || September 24, 2000 || Anderson Mesa || LONEOS || GEF