The frame below is built around galaxy triplet in Leo. There are actually a few galaxy triplets in Leo, the brightest galaxy in this one is M105 elliptical galaxy. This one has not been put into original Messier catalogue. It was added there in 1947 by Helen S. Hogg. M105 has been discovered March 24th, 1781 by Pierre Mechain, a few days after he discovered M95 and M96 galaxies nearby. It is located about 32 million light years away. Hubble Space Telescope research indicated, that there is massive object in the galaxy center, probably a black hole with mass about 200 millions of solar mass.
M105 galaxy togehter with NGC3384 (to the left) are surrounded with large molecular hydrogen cloud that radius is estimated for 650 thousands light years. NGC3384 is also an elliptical galaxy, that one has been discovered by William Herschel in 1784. Star color in this galaxy center have been determined and it turned out it that over 80% of them belongs to the population II, so the stars older than one billion years.
Third object in this obvious triplet formation is spiral galaxy NGC3373 (NGC3389). All these three items are members of Leo I Group altogehter with some other galaxies (like for example M95 and M96 that did not fit this frame).
The total exposure time was almost 10 hours, so there is much more in there. Although the picture has been shot from my backyard where dark sky is not actually dark, the faintest recorded stars are about 22mag (so for example 100 million times fainter than Polaris). Also many many distant galaxies have been pictured. There are much more galaxies than our Milky Way stars in the image. As you can see below – each white cross indicates a galaxy identified in SDSS project. And there are two possible distant galaxy clusters marked with red ovals – at 1.3 and 1.8 billion light years.
One may as why birthday? Because light has been collected at my birthday and one day after 🙂