The stellar field in the vicinity of Sirius and the color enigma.

Several ancient texts suggest that the bright star Sirius was red in the recent past. Evidence is presented from an observation record found in Chinese sources (of about 100 BC) in which mention is made of a color change of Sirius. Photometric observations are reported of the stellar field around Sirius with the aim to find the possible causes of the color change(s) of the stellar system within historical times. Among the possible causes are objects external to Sirius A-B, namely a small interstellar cloud or a third body interacting with the system. Both could have caused an observed reddening effect consistent with the historical record, and two stars in the field may have the right characteristics and orbits to interact with Sirius.