A lot will depend on your location. In the northern hemisphere Canis Major can be seen during the Winter months.
Auriga, Camelopardalis, Canis Major, Columba, Gemini, Lepus, Monoceros, Pictor
Canis Majoris can refer to any number of stars which, as seen from Earth, reside within the Canis Major constellation.
Canis Major (Latin for greater dog) was the largest of Orion's hunting dogs (Laepaps).According to ancient Greek, Canis Major ran incredibly fast, and won a race against a fox that was the fastest creature in the world. (They obviously had not seen a cheetah yet)Because of this Zeus placed the dog in the sky to commemorate the victory.
Like all constellations, they can be seen quite well over several months, just at different stages of the night. Canis Major is good for seeing in the months from November through to February in particular. By February it is seen much earlier in the evening, but for less time.
That completely depends on what time of night you want to go outside and look at it. If you're like most people, and prefer to do it between dinner and bed-time, then Winter to early Spring is the best time.
Canis Major (more specifically Sirius) has a declination of -17 degrees. That puts it 17 degrees below the celestial equator. It can be seen from most of the Earth, except for those above north latitude +73. It is the brightest star in the night sky, second only to the Sun, except that the Moon, Venus, and Jupiter are brighter. It has a right ascension of 6 hours and 45 minutes sidereal time, which puts it nearly 7 hours east of the first point of Aries.I'm sorry, but I do not know how to translate that to the best time of year. I have submitted this to the category supervisor for refinement. Anyone else, of course, that has the remainder of the answer is welcome to make that refinement.
All constellations that can be seen from the northern hemisphere can be seen - in theory - in Mexico City. In reality, weather conditions and "light pollution" make such sightings very difficult, if not impossible.
April
The star Sirius is the brightest star visible from the earth. Sirius is in the Canis Major constelation, and is therefore often refered to as "the Dog Star"
Some constellations that can be seen during December include Orion, Taurus, Gemini, and Canis Major. Orion is notable for the three bright stars in a row that form his "belt." Taurus features the prominent star cluster Pleiades, also known as the Seven Sisters. Gemini is known for its two bright stars, Castor and Pollux, and Canis Major showcases the brightest star in the night sky, Sirius.
Yes, It is is the largest star discovered to date, the fact that we can see it is why we know about it.