a white dwarf star of its type. With a surface temperature of , it is also much cooler than Sirius B; this is a testament to its lesser mass and greater age. The mass of the progenitor star for Procyon B was about and it came to the end of its life some billion years ago, after a main-sequence lifetime of million years. X-ray emission Attempts to detect X-ray emission from Procyon with nonimaging, soft X-ray-sensitive detectors prior to 1975 failed. Extensive observations of Procyon were carried out with the Copernicus and TD-1A satellites in the late 1970s. The X-ray source associated with Procyon AB was observed on 1 April 1979, with the Einstein Observatory high-resolution imager (HRI). The HRI X-ray pointlike source location is ~4″ south of Procyon A, on the edge of the 90% confidence error circle, indicating identification with Procyon A rather than Procyon B which was located about 5″ north of Procyon A (about 9″ from the X-ray source location). Etymology and cultural significance α Canis Minoris (Latinized to Alpha Canis Minoris) is the star's Bayer designation. The name Procyon comes from the Ancient Greek (), meaning "before the dog", since it precedes the "Dog Star" Sirius as it travels across the sky due to Earth's rotation. (Although Procyon has a greater right ascension, it also has a more northerly declination, which means it will rise above the horizon earlier than Sirius from most northerly latitudes.) In Greek mythology, Procyon is associated with Maera, a hound belonging to Erigone, daughter of Icarius of Athens. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included Procyon for the star α Canis Minoris A. The two dog stars are referred to in the most ancient literature and were venerated by the Babylonians and the Egyptians, In Babylonian mythology, Procyon was known as Nangar (the Carpenter), an aspect of Marduk, involved in constructing and organizing the celestial sky. The constellations in Macedonian folklore represented agricultural items and animals, reflecting their village way of life. To them, Procyon and Sirius were Volci "the wolves", circling hungrily around Orion which depicted a plough with oxen. Rarer names are the Latin translation of Procyon, Antecanis, and the