编辑“︁NGC 300”︁（章节）

==SN 2010da==
2010年5月23日，Monard在NGC 300內發現了一個視星等16等的光學瞬變體，該天體獲得[[超新星]]的編號SN 2010da<ref name=atel2640>{{cite web
  |date=2010-05-26
  |title=ATEL 2640: Optical Photometry of the New Optical Transient SN 2010da in NGC 300
  |publisher=Astronomers Telegram
  |url=http://www.astronomerstelegram.org/?read=2640
  |accessdate=2010-05-25
  |archive-date=2011-07-20
  |archive-url=https://web.archive.org/web/20110720114643/http://www.astronomerstelegram.org/?read=2640
  |dead-url=no
  }}</ref>。這個光學瞬變體距離NGC 300的中心西方15.9"，北方16.8"，天球座標是[[赤經|RA]]:{{RA|00|55|04.86}}，[[赤緯|DEC]]:{{DEC|-37|41|43.7}}<ref name=sn-list>{{cite web
  |title=List of Supernovae
  |publisher=Central Bureau for Astronomical Telegrams
  |url=http://www.cbat.eps.harvard.edu/lists/Supernovae.html
  |accessdate=2011-07-03
  |archive-date=2015-07-11
  |archive-url=https://www.webcitation.org/6ZwGPJ5pB?url=http://www.cbat.eps.harvard.edu/lists/Supernovae.html
  |dead-url=no
  }}</ref>。

緊接著兩組獨立的光譜資料則指出它可能是另一次光學瞬變現象，而非超新星，而且其中一組光譜顯示它比較可能是[[高光度藍變星]]爆發<ref name=atel2636>{{cite web
  |date=2010-05-25
  |title=ATEL 2636: SN 2010da is a SN ''impostor''
  |publisher=Astronomers Telegram
  |url=http://www.astronomerstelegram.org/?read=2636
  |accessdate=2010-05-25
  |archive-date=2011-07-20
  |archive-url=https://web.archive.org/web/20110720114548/http://www.astronomerstelegram.org/?read=2636
  |dead-url=no
  }}</ref><ref name=atel2637>{{cite web
  |date=2010-05-25
  |title=ATEL 2637: Spectroscopy of SN 2010da in NGC 300
  |publisher=Astronomers Telegram
  |url=http://www.astronomerstelegram.org/?read=2637
  |accessdate=2010-05-25
  |archive-date=2011-07-20
  |archive-url=https://web.archive.org/web/20110720114557/http://www.astronomerstelegram.org/?read=2637
  |dead-url=no
  }}</ref>，並且使用中紅外線波段尋找該天體的前身星<ref name=atel2632>{{cite web
  |date=2010-05-24
  |title=ATEL 2632: Mid-IR progenitor of SN 2010da in NGC 300
  |publisher=Astronomers Telegram
  |url=http://www.astronomerstelegram.org/?read=2632
  |accessdate=2010-05-25
  |archive-date=2011-07-20
  |archive-url=https://web.archive.org/web/20110720114616/http://www.astronomerstelegram.org/?read=2632
  |dead-url=no
  }}</ref>。該瞬變現象於9天內下降了0.5到0.7等，下降率遠高於同星系內2008年另一個光學瞬變事件<ref name=atel2660>{{cite web
  |date=2010-06-04
  |title=ATEL 2660: Optical and Near-IR Follow-up of SN 2010da: Evidence for Warm Dust
  |publisher=Astronomers Telegram
  |url=http://www.astronomerstelegram.org/?read=2660
  |accessdate=2010-06-11
  |archive-date=2011-07-20
  |archive-url=https://web.archive.org/web/20110720114735/http://www.astronomerstelegram.org/?read=2660
  |dead-url=no
  }}</ref>。