No abstract

V618 Sgr was previously classified as an R CrB-type variable and later as a possible symbiotic star. Our study aims to analyse the nature of this target, which is currently undergoing significant brightening in properties similar to those of known symbiotic novae. We analyse literature information, photometric observations, and 35 new optical spectra. Our findings strongly suggest that V618 Sgr is an eclipsing symbiotic nova currently in outburst. Additionally, since the star has demonstrated at least two similar brightenings in the past, we propose that V618 Sgr could be the first known galactic symbiotic nova observed in repeated outbursts of this type and may host a relatively massive white dwarf.

We present Grantecan 10 m telescope (GTC) spectroscopic confirmations of 55 faint Planetary Nebulae (PNe) candidates discovered largely in the INT Photometric Hα Survey of the Northern Galactic Plane (IPHAS) by our pro-am collaboration. We confirm 46 of them as ‘True’ (T), 4 as ‘Likely’ (L) and 5 as ‘Possible’ (P) PNe and including 5 new PNe central star (CSPN) discoveries. This was from observations of 62 new candidates yielding a maximum PN discovery success rate of 89 per cent. The sensitivity and longer wavelength coverage of IPHAS allows PNe to be found in regions of greater extinction and at these lower Galactic latitudes, including PNe in a more advanced evolutionary state and at larger distances compared to previously known Galactic PNe. We use an holistic set of observed characteristics and optical emission-line diagnostics to confirm candidates. Plasma properties have been determined in a self-consistent way using PyNeb. This work is facilitated by the functionality of our powerful, multi-wavelength database ‘HASH’ (Hong Kong, Australian Astronomical Observatory, Strasbourg Observatory H-alpha Planetary Nebula catalogue) that federates known imaging, spectroscopy and other pertinent data for all Galactic T, L, P PNe and the significant numbers of mimics. Reddenings, corrected radial velocities and PNe electron density and temperature estimates are provided for these new PNe where possible.

We present the key results from an intensive and coordinated ten-year amateur observational programme designed to uncover and confirm Galactic planetary nebulae (PNe). This was undertaken and led by a dedicated group of largely French amateur astronomers in collaboration with professional colleagues. Over this period this group has uncovered a total of 209 spectroscopically confirmed True, Likely, and Possible Galactic PNe, with the work accelerating over the last three years in particular. These new discoveries represent ~5% of all 3831 True, Likely, and Possible Galactic PNe currently known according to the HASH database as of March 2022. A further 610 PNe candidates are awaiting follow-up. These figures demonstrate the power and value of the amateur community in undertaking a coordinated and focused programme such as this.