M31N-2007-06b: A Nova in the M31 Globular Cluster Bol 111

TL;DR

This paper reports the discovery and spectroscopic analysis of a rare nova in the M31 globular cluster Bol 111, providing insights into nova characteristics and their occurrence in such clusters.

Contribution

It presents the first spectroscopic confirmation of a nova in an M31 globular cluster, expanding understanding of nova populations in dense stellar environments.

Findings

The nova belongs to the He/N spectroscopic class.

Broad emission lines with FWHM ~3000 km/s observed.

This is the first nova in M31's globular cluster with spectroscopic data.

Abstract

We report spectroscopic observations of the nova M31N-2007-06b, which was found to be spatially coincident with the M31 globular cluster Bol 111. This nova is the first out of more than 700 discovered in M31 over the past century to be associated with one of the galaxy's globular clusters. A total of three spectra of the nova were obtained 3, 6, and 36 days post discovery. The data reveal broad (FWHM ~3000 km/s) Balmer, NII, and NIII emission lines, and show that the nova belongs to the He/N spectroscopic class. The He/N class of novae are relatively rare, making up roughly 15% of the novae with measured spectra in M31, and roughly 20-25% of the Galactic novae for which spectroscopic data are available. The implications of a nova, particularly an He/N nova, occurring in a globular cluster are discussed.