U BV RI PHOTOMETRIC STANDARD STARS AROUND THE SKY AT+50 deg DECLINATION

U BV RI photoelectric observations have been made of 335 stars around the sky, and centered approximately at +50 deg declination. The majority of the stars fall in the magnitude range 9 < V < 16, and in the color range -0.3 < (B - V) < +1.8. Those 243 stars best suited as new broadband photometric standard stars average 12.5 measures each from data taken on 98 different nights over a period of 17 years at the Kitt Peak National and Lowell Observatories.