BT Monocerotis
BT Monocerotis was a nova, which lit up in the constellation Monoceros in 1939. It was discovered on a spectral plate by Fred L. Whipple on December 23, 1939. BT Monocerotis reached a brightness of 4.5 mag. Its brightness decreased after the outbreak in 36 days by 3 mag. The light curve for the eruption had a long plateau period.
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