# New Luminous Blue Variable Candidates in NGC 4736

## TL;DR

This study reports the discovery of three new luminous blue variable (LBV) candidates in NGC 4736, characterized by their spectral features and variability, expanding the known population of LBVs in this galaxy.

## Contribution

The paper identifies and characterizes three new LBV candidates in NGC 4736 using spectral analysis and archival data, providing new potential members of this rare stellar class.

## Key findings

- One candidate shows clear variability confirming LBV status.
- Two candidates exhibit spectral features and variability consistent with LBVs.
- All three candidates have bolometric magnitudes between -8.2 and -11.5.

## Abstract

We have found three new LBV candidates in the star-forming galaxy NGC 4736. They show typical well-known LBV spectra, broad and strong hydrogen lines, He I lines, many Fe II lines, and forbidden [Fe II] and [Fe III]. Using archival Hubble Space Telescope and ground-based telescope data, we have estimated the bolometric magnitudes of these objects from -8.4 to -11.5, temperatures, and reddening. Source NGC 4736_1 (Mv = -10.2 +/- 0.1 mag) demonstrated variability between 2005 and 2018 as Delta V = 1.1 mag and Delta B = 0.82 mag, the object belongs to LBV stars. NGC 4736_2 (Mv < -8.6 mag) shows P Cyg profiles and its spectrum has changed from 2015 to 2018. The brightness variability of NGC 4736_2 is Delta V = 0.5 mag and Delta B = 0.4 mag. In NGC 4736_3 (Mv = -8.2 +/- 0.2 mag), we found strong nebular lines, broad wings of hydrogen; the brightness variation is only 0.2 mag. Therefore, the last two objects may reside to LBV candidates.