Photometric and spectroscopic observations of the symbiotic star CM Aql in outburst

CM Aql is a poorly studied symbiotic star harboring an M2 giant. On 2020 Feb 28, it was caught in outburst by Gaia as alert Gaia20bcf (=AT 2020dsz). We begun photometric BVRI observations on March 7 as soon as the object rose above 2.5 airmass on the pre-dawn sky. The table summarizes our photometry collected with ANS Collaboration telescope ID 310 (total error budget - including transformation to the Landolt equatorial standards - less than 0.013 mag in all colors and all dates).