Related papers: AT 2017fvz: a nova in the dwarf irregular galaxy N…

We present a detailed study of the 2017 eruption of the classical nova ASASSN-17pf (LMCN 2017-11a), which is located in the Large Magellanic Cloud, including data from AAVSO, ASAS-SN, SALT, SMARTS, SOAR, and the Neil Gehrels \textit{Swift}…

On 2018, April 29, a bright classical nova (CN) Per 2018 was discovered. Its progenitor is a well-known dwarf nova V392 Per. In this contribution, we analyze $UBVR_{C}I_{C}$ photometry and optical spectroscopy of the CN V392 Per. From the…

Some transients, although classified as novae based on their maximum and early decline optical spectra, cast doubts on their true nature and whether nova impostors might exist. We monitored a candidate nova which displayed a distinctly…

The classical nova, AT 2023prq, was discovered on 2023 August 15 and is located at a distance of 46 kpc from the Andromeda Galaxy (M 31). Here we report photometry and spectroscopy of the nova. The 'very fast' ($t_{2,r^{\prime}}\sim3.4$ d)…

We have discovered 13 new candidate Planetary Nebulae (PNe) in the dwarf irregular galaxy NGC 6822, increasing its total number to 17 objects. Our sample of candidate PNe is complete down to 3.5 mag below the brightest PN.

We report the discovery of a galaxy at a redshift z = 6.17 identified from deep narrow band imaging and spectroscopic follow-up in one of the CFHT-VIRMOS deep survey fields at 0226-04. In addition to the existing deep BVRI images of this…

The All Sky Automated Survey for SuperNovae (ASAS-SN) reported a possible Galactic dwarf nova ASASSN-18fs on 2018 March 19 at $\sim$13.2 mag in the V band, with a quiescent magnitude of V$>$17.6. Here we report on the follow-up photometry…

Novae are the observable outcome of a transient thermonuclear runaway on the surface of an accreting white dwarf in a close binary system. Their high peak luminosity renders them visible in galaxies out beyond the distance of the Virgo…

To test the existence of a possible radial gradient in oxygen abundances within the Local Group dwarf irregular galaxy NGC 6822, we have obtained optical spectra of 19 nebulae with the EFOSC2 spectrograph on the 3.6-m telescope at ESO La…

We report the discovery and follow-up observations of VT 1137-0337: an unusual radio transient found in our systematic search for extragalactic explosions in the VLA Sky Survey (VLASS). VT 1137-0337 is located in the brightest region of a…

Our proposed method to study the star formation histories in nearby irregulars is here applied to NGC 6822. To this purpose we have obtained accurate CCD photometry of three regions in the galaxy, reaching V$\simeq$23.5 with an accuracy of…

Classical novae are eruptions on the surface of a white dwarf in a binary system. The material ejected from the white dwarf surface generally forms an axisymmetric shell of gas and dust around the system. The three-dimensional structure of…

The Type~Ia supernova (SN~Ia) 2017cfd in IC~0511 (redshift z = 0.01209+- 0.00016$) was discovered by the Lick Observatory Supernova Search 1.6+-0.7 d after the fitted first-light time (FFLT; 15.2 d before B-band maximum brightness).…

We report on multiwavelength observations of nova SMCN 2016-10a. The present observational set is one of the most comprehensive for any nova in the Small Magellanic Cloud, including: low, medium, and high resolution optical spectroscopy and…

Images obtained with the CTIO 4-m telescope and the MOSAIC-2 wide field camera in [O III] 5007 and H\alpha on-band and off-band filters are analyzed to search for emission lines objects in the galaxy NGC 6822. In particular we search for PN…

We present early spectral observations of the very slow Galactic nova Gaia22alz, over its gradual rise to peak brightness that lasted 180 days. During the first 50 days, when the nova was only 3--4 magnitudes above its normal brightness,…

We present a detailed photometric study of the dwarf irregular galaxy NGC 6822 aimed at investigating the properties of its stellar populations and, in particular, the presence of stellar radial gradients. Our goal is to analyse the stellar…

Peaking at 3.7 mag on 2020 July 11, YZ Ret was the second-brightest nova of the decade. The nova's moderate proximity (2.7 kpc from Gaia) provided an opportunity to explore its multi-wavelength properties in great detail. Here we report on…

We report results of optical imaging and low-resolution spectroscopic monitoring of supernova (SN) 2017iro that occurred in the nearby ($\sim$\,31 Mpc) galaxy NGC 5480. The \ion{He}{1} 5876 \AA\, feature present in the earliest spectrum…

MASTER OT 075353.88+174907.6 was a blue optical transient reported by the MASTER-Net project on 2017 Oct 31. This source was previously detected by {\it GALEX} in its NUV band but not by the Sloan Digital Sky Survey (in the optical). We…