2MASS6X K (2.16um) survey collection

During the final months of 2MASS observatory operations, a campaign of targeted "long exposure" observations was carried out during times when no previously unscanned parts of...在2微米全天巡天（2MASS）天文台观测任务的最后数月期间，一项定向"长曝光"观测计划于不存在此前未被扫描区域的时段内开展。