Review of light curves of novae in the modified scales. I. Recurrent novae

TL;DR

This paper reviews and normalizes light curves of 10 recurrent novae, identifies groups with similar patterns, estimates their absolute magnitudes, and suggests new candidates for recurrent novae based on light curve analysis.

Contribution

It introduces a unified normalization method for nova light curves and classifies recurrent novae into distinct groups, also proposing new candidates based on light curve comparisons.

Findings

Recurrent novae retain their light curve shape across outbursts.

Three distinct groups of recurrent novae were identified.

Several new recurrent nova candidates were proposed.

Abstract

We reviewed the light curves of 10 known recurrent novae (RNs) in the modified scales of the "logarithmic of time, amplitude of outburst". A unified rule was established to normalize the time scale. Confirmation of the known result: in a series of recurrent outbursts, the light curve of nova retains its shape, was realized by distinguishing three groups amongst these 10 novae. The CI Aql (+V2487 Oph) and T Pyx (+ IM Nor) groups contain by one additional member. The V745 Sco group includes V394 CrA and V3890 Sgr. Three RNs: T CrB, RS Oph and U Sco, have its own uniqueness. After comparing the light curves of galactic novae with the light curves of some novae of the Large and Small Magellanic Clouds (LMC and SMC), we selected several candidates for recurrent novae in addition to 3 known recurrent novae in these galaxies. Assuming that the physical characteristics of the novae in the group coincide, we estimated the absolute magnitudes of the galactic novae: CI Aql and V2847 Oph have absolute magnitudes M_V=-7.5 mag, IM Nor and T Pyx - M_V=-7.2 mag, V3890 Sgr - M_V=-7.9 mag, U Sco - M_I=-9.0 mag. The comparison of the summarized light curves of recurrent novae with the light curves of some low-amplitude classical novae allowed us amongst the last to distinguish the list of 26 candidates in recurrent novae. Three of them are known from lists of other authors. An interesting example is the V1017 Sgr, which erupted in 1919 as a nova of the T Pyx type, and which also shows less bright outbursts classified as dwarf nova outbursts.