The dark cloud TGU H994 P1 (LDN 1399, LDN 1400, and LDN 1402): Interstellar extinction and distance

Abstract

The results of CCD photometry in the seven-colour Vilnius system, for about 1000 stars down to V = 20 mag and their twodimensional spectral types, are used to investigate the interstellar extinction in a 1.5 square degree area in the direction of the dark cloud TGU H994 P1 (LDN 1399, LDN 1400 and LDN 1402) in Camelopardalis. Photometric classification of 18 brightest stars down toV = 12 mag was verified by the spectra obtained with the 1.22 m telescope of the Asiago Observatory. The interstellar extinction run with distance is investigated with the results of photometry in the Vilnius system, and 504 red clump giants, identified by combining the results of infrared photometry from the 2MASS and WISE surveys. A possible distance of 140 ± 11 pc to the TGU H994 P1 cloud seems to be acceptable. Alternative distances of the cloud are discussed. The complex of the Camelopardalis clouds probably has a considerable depth along the line of sight, similar to that observed in the Taurus-Auriga complex. The maximum extinction AV in the dark filaments is found to be about 6.5 mag.