New Variable Stars Discovered by Data Mining Images Taken during Recent Asteroid Photometric Observations. II. Results from July 2015 through December 2016

Volume 45 number 2 (2017)

Riccardo Papini: Wild Boar Remote Observatory (K49), via Potente 52, San Casciano in val di Pesa, Florence, 50026, Italy; riccardo.papini@yahoo.it
Alessandro Marchini: Astronomical Observatory, DSFTA - University of Siena (K54), via Roma 56, Siena, 53100, Italy; alessandro.marchini@unisi.it
Fabio Salvaggio: Wild Boar Remote Observatory (K49), Saronno, Italy; Gruppo Astrofili Catanesi, Catania, Italy
Davide Agnetti: Osservatorio Aldo Agnetti di Lomazzo, Como, Italy
Paolo Bacci: GAMP Gruppo Astrofili Montagna Pistoiese (104), San Marcello Pistoiese, Italy
Massimo Banfi: Osservatorio di Nova Milanese (A25), Nova Milanese, Italy; Osservatorio delle Prealpi orobiche (A36), Ganda di Aviatico, Italy
Giorgio Bianciardi: Telescopio Remoto UAI, Remote Telescope Unione Astrofili Italiani, Italy
Matteo Collina: Avalon Instruments Merlino, Aprilia, Italy
Lorenzo Franco: Balzaretto Observatory (A81), Rome, Italy
Gianni Galli: GiaGa Observatory (203), Pogliano Milanese, Italy; Osservatorio Ca' del Monte (B14), Pavia, Italy
Mauro Ghiri, Alessandro Milani: Avogadro Observatory, Manciano, Italy
Claudio Lopresti: IRAS Istituto Spezzino Ricerche Astronomiche, La Spezia, Italy
Giuseppe Marino: Gruppo Astrofili Catanesi, Catania, Italy
Luca Rizzuti: Associazione Astropollino, Lauria, Italy
Nello Ruocco: Osservatorio Astronomico Nastro Verde (C82), Sorrento, Italy
Ulisse Quadri: Osservatorio Bassano Bresciano (565), Bassano Bresciano, Italy

Abstract

This paper follows the previous publication of new variables discovered at Astronomical Observatory, DSFTA, University of Siena, while observing asteroids in order to determine their rotational periods. Usually, this task requires time series images acquisition on a single field for as long as possible on a few nights not necessarily consecutive. Checking continually this “goldmine” allowed us to discover 57 variable stars not yet listed in catalogues or databases. While most of the new variables are eclipsing binaries, a few belong to the RR Lyrae or delta Scuti class. Since asteroid work is definitely a time-consuming activity, coordinated campaigns of follow-up with other observatories have been fundamental in order to determine the elements of the ephemeris and sometimes the right subclass of variability. Further observations of these new variables are therefore strongly encouraged in order to better characterize these stars, especially pulsating ones whose data combined with those taken during professional surveys seem to suggest the presence of light curve amplitude and period variations.