Near-infrared photometry of 20 hipparcos carbon stars

Near-infrared JHK photometry was carried out for 20 carbon stars observed by the satellite Hipparcos. From the observations, bolometric corrections in the K band (BCK), apparent bolometric magnitudes (mrmbo) and effective temperatures (Te) of these stars were estimated. Combined with the trigonometric parallaxes measured by Hipparcos, the absolute bolometric magnitudes (Mbol) of some of the stars were obtained.