On the photographic detection of novae: a specific case in Libra

Comparing ESO GPO astrograph plates taken in September 1990 at La Silla with the Palomar Sky Survey from 1955, a nova was ostensibly discovered at α = 15^h07^m31^s, δ = −1°44′01″.6 (equinox 1950.0). Its magnitudes in 1955 estimated from the Palomar plates are m_B = 16_·^m9 and m_R = 17_·^m. Finally (March 1991), it was identified as a high redshift (z ∼ 0.3) galaxy (Rafanelli, private communication) by spectroscopic means. Radio observations are requested.