The name, the story, the myth
Inserted in a space of sky in which the constellations had already been defined for some time, this new constellation was 'created' in the 17th century by the German astronomer Johannes Hoevelke (Hevelius) and, since it was destined to approach the two stars named after the Chara dogs, a female (whose name appears to be the transliteration in Latin of the Greek word "joy") and Asterion (male dog, which in Greek means "starry"), was given the name Hunting Dogs, kept on a leash by the Bifolco (Bootes) while barking against the Big Dipper. The fact of being kept on a leash is perhaps meant to prevent the dogs, two hounds, from chasing the Bear around the Pole. Julius Staal (1917- 1986), an important scholar of stellar mythology, considers these stars as the dogs that guided the daughter (the Virgin) of Icarius (Boote) to the body of their deceased master, instead of the older (but astronomically less suitable, given the distance) Lesser Dog.
The constellation Hunting Dogs
It's definitely a constellation poor of bright stars, but it's enough to find the Big Dipper and look for the center of the arch formed by the handle and two or three other stars: you can't miss a star of almost third magnitude, in an area of sky practically empty. This is Cor Caroli, the Heart of Charles, century α CVn, where the initials should be read "alfa canum venaticorum".
I say this because I have a little linguistic anecdote to report: the constellation, sometimes called "the greyhounds", in Latin is called "Canes Venatici" (to the name), while it is used as always to the genitive when it follows the identification letters or numbers. For example the Leo in Latin is Leo, but when we speak of β Leo, 35 Leo, R Leo, we must always say with the genitive, "Leonis", beta leonis and not beta leo. Even worse is mispronouncing the name: I happened to follow some time ago a streaming transmission from an astronomical site and the (fine) dictioner, talking about this constellation, pronounced it with a horrible accent (venatìci), while obviously the correct diction is "venàtici". To err is human but to persevere is diabolical and the otherwise good astronomer who spoke about the Hunting Dogs had not proved to be a perfect linguist at all, repeating the error over and over again. I recommend myself therefore: it is not for strange fussiness, but Astronomy is a Science and must be treated well. It's as if talking about football one dared to pronounce Maràdona... at the very least they would laugh in his face and it would certainly not make a good impression.
while Stellarium provides this kind of image
Speaking of images...
... it has to be said that this constellation is really full of really fascinating deep sky objects, some of them very well known and photographed by the sharp eye of the HST. Clicking on each image, a high resolution version will appear. They are really to be admired one by one!
Let's start with the famous Whirlpool Galaxy (M51 or NGC 5194), accompanied by the barred spiral galaxy NGC 5195: a cosmic spectacle!
A little less well known is the Sunflower Galaxy (Sunflower Galaxy, M63 or NGC 5055), but equally rich in details
the Sunflower Galaxy
Another beautiful spiral galaxy, seen almost opposite is the superb M94, also known as NGC 4736
the spiral galaxy M94
Another spectacle of nature is the splendid M106 (NGC 4258), rich in colourful filaments.
the spiral galaxy M106
In the middle of all these galaxies, a nice globular cluster, M3, otherwise known as NGC 5272...
the globular cluster M3
Let's move on to another galaxy, the Whale Galaxy, NGC 4631, which takes its name (Whale) not from the constellation, but from its appearance vaguely reminiscent of this cetacean, without even having to join dots, armed with fantasy...
the Whale Galaxy
But let's continue with another series of spiral galaxies, NGC 5033.
the galaxy NGC 5033
Then we move on to NGC 5005
the galaxy NGC 5005
and now we've arrived at NGC 4151...
the galaxy NGC 4151
Now instead we see a pair of dwarf and prospectively neighboring galaxies, NGC 4618 and NGC 4625
galaxies NGC 4618 and NGC 4625
here we see a magnificent spiral galaxy, NGC 5371.
the galaxy NGC 5371
and finally we close with a couple of interacting galaxies, NGC4656 and NGC 4657, called by some Crowbar Galaxy (Crowbar Galaxy) or, more politically correct, Hockey Stick Galaxy (Hockey Stick Galaxy)
galaxies in interaction NGC 4656 and NGC 4657
Really there is the embarrassment of the choice between which of these photos to put on the desktop: thanks also to the advertising (which has little to do with Astronomy, though!) I would venture a preference for Whirlpool: please just name it always in English, without looking for translations like whirlpool, whirlpool or whirlpool, which in my opinion belittle the beauty of this object. An improbable Vortex galaxy then I think a lot of Star Trek star travel...
Two stars nearby
In this constellation rich in galaxies, there are also a couple of nearby stars: the first is the class G0 β CVn star, which is at a small distance (on a cosmic basis it is small, but in reality it is an enormous distance, on the Earth scale) of 27 al. Since the Hunting Dogs are located in the Northern Hemisphere, it should be clear that for a cosmic game of perspective, our Sun, seen from the vicinity of this star, is in a zone of sky in the company of our Australian stars, Achernar, Fomalhaut, Diphda and very close to Ankaa, of the constellation Phoenix. My Betacìvini friends sent me the photo of our yellow dwarf that they thought formed a binary system with the mentioned star.
The second near star, definitely farther away, is also of spectral class G0, the 10 CVn, 57 al distant from us: seen from the vicinity of this star, the Sun appears at the limit of visibility to the naked eye (6a ), in a star field particulary identical to the previous one, but where now appears also another well known southern star, Sirius. My friends Diecivini, at my request, have sent me the photo: they are, yes, passionate about Astronomy, but their real passion is the oenology, as can be easily deduced from their name. Just think that their bottles are only 10 liters, but they handle and drain them with skill, thanks to their four powerful arms.
An exaggerated star and two big girls...
In the comparison diagram between the biggest stars of the Hunting Dogs and other known and other really huge stars, we can't help but notice the red carbon giant Y CVn, also known as the Superb, class C7, which is well over 400 times bigger than our Sun. My nice friends Superbi don't complain too much about their decidedly monstrous and disturbing star, if seen at a distance of 10 UA (which I remember to be Saturn's distance from the Sun): the spectral class C7 indicates a star whose surface temperature is below 3000 K, little thing compared to the 5700 and broken Kelvin degrees of our Sun. The name that this star has received from the Italian Astronomer Secchi, derives from its beautiful red colouring, for a small star of almost 5a.
The other two stars with a remarkable size are the 2 CVn and the 3 CVn both of spectral class M, respectively 70 and 65 times the size of our Sun and therefore slightly less than the famous Rigel. My friends Duecovoni and Trecovoni are very proud of them: needless to say that their name derives from the common origins of a single population dedicated to agriculture. The story of this bucolic population tells that the 5 survivors escaped from their burning planet and went 2 to one star and 3 to another, thus giving rise to two lineages of farmers who make the cultivation of wheat their main occupation.
Names of the stars
The Hunting Dogs have just three stars that have received a designation: they are
- Cor Caroli (α CVn): the heart of Charles (King Charles I)
- Chara (β CVn): joy
- the Superb (Y CVn): the superb
At the usual time and chosen as a reference, 9 p.m., to indicate the visibility of the individual constellations, we have that the Hunting Dogs are an almost circumpolar constellation, which is found low on the horizon around New Year's Eve, and then appear at the zenith in early June and finally find themselves almost at sunset in late October, low on the horizon to the Northwest.