Thanks for the kind words.
Autumn part ii
I’ve seen that with my original list of objects I didn’t go out into the deeper reaches of the Autumn sky, so I’m adding a part ii to compliment the first lot of items. I’ll also include some naked eye objects as there is actually so much to see without a telescope or binoculars. There is so much that is actually hiding right under your nose only because you just don’t know what you are looking at. And oh golly gosh, there is a lot happening right overhead!
Autumn list continued
* Markarian’s Chain, a string of galaxies in Virgo. This is a staggering arrangement of galaxies that are all linked gravitationally, and to us forms a line of sight ribbon of galaxies that stretches about 1.5°. These are all relatively bright galaxies, and this string is very easy to follow in a 4” refractor, and also larger binos. As aperture increases, fainter and fainter galaxies become visible. In my 17.5” dob, this is a gob-smacking cacophony of galaxy after galaxy after galaxy. No matter the size aperture you have, Markarian’s Chain is a fantastic target to chase down.
* Leo, yes a constellation, but it harbours two excellent trios of galaxies, the first is a rather widely spaced trio, comprised of M95, M96 & M105. The next trio, a little further east from the first lot is made up of M65, M66 & NGC 3624. It is curious that Charles Messier missed out on spotting NGC 3624, considering it is just as bright at the other 5 messier galaxies listed here.
* The Virgo Quasar, 3C 273. This is one of the most exotic objects in the sky, and the most distant visible in amateur instruments. Through a scope, it isn’t anything particularly exciting, appearing as a magnitude 13 star. But when someone asks that “cute” question of “how far can you see with your telescope”, you can now tell them “at least 2.5 billion light years”! The challenge comes from actually identifying the quasar out from the surrounding stars. Quasars are the brightest, oldest and most distant objects astronomers have found. If 3C 273 was just 32 light years from Earth, it would shine just as bright as the Sun.
Like I said in my first post, some of the objects I list WILL challenge. These will push your observing skills.
* Alpha Centauri. The closest star Earth after the Sun, at a distance of 4.3 light years. That doesn’t sound too far, does it? Think of it this way, the Voyager II spacecraft is the fastest spacecraft launched from Earth. It will take Voyager II some 63,000 years to reach Alpha Centauri. Alpha Centauri is also not a single star, but a multiple star system. Through even a small 2” scope, it is possible to split it into two separate stars, nearly of equal brilliance. But it doesn’t stop there. Alpha Centauri is a tertiary stellar system, with a much fainter third star, Proxima Centauri, shining at magnitude 11, and is actually just over 2° from its two brighter siblings. Multiple star systems are actually the norm, and our single star Sun is the exception than the norm! Procyon, the brightest star in Canis Minor, is a nonary system (made up of nine stars)!
Naked eye items
* STARS! Yeah, well so what? Well, every single individual star that you see in the sky without a scope or binos is entirely within our Milky Way galaxy. Yes, there are a few faint glows of distant galaxies that can be seen naked eye, but none of their individual stars can be resolved naked eye.
* The Coal Sack. This is a very prominent dark nebula that sits across Centaurus and the Southern Cross. While we may initially think that stars are what make up the bulk of galaxies, star probably form less than 10% of the mass of a galaxy! The vast majority of the mass of galaxies is formed from the gas and dust that has not being formed into stars! The Coal Sack is a cloud of this gas and dust.
* The Dark Emu. This is an Aboriginal constellation. But it isn’t formed by bright stars, but of the dark nebulosity just like the Coal Sack. The head of the Emu is formed by the Coal Sack, its neck stretching out to the east, with its body deep inside Scorpius and Sagittarius, and the Emu’s legs continuing on further to the north-east. This is a massive constellation and it requires a dark sky in order to see it to its full magnificence.
Rock ‘n’ roll lifestyle
* While in the area of the Dark Emu, there’s a set of very bright stars that are living the rock and roll lifestyle, and we have front row seats for when these all go supernova! Acrux, Becrux, the two brightest stars in the Southern Cross, are supergiant stars that will eventually go supernova. Supergiant stars are the largest of stars, and burn through their hydrogen at a phenomenal rate. The main sequence phase of these stars is only a few tens of millions of years, while the main sequence phase of our Sun is 10 billion years. These two stars are actually very close to us, at roughly 300 light years, so when these two explode, it will be a truly spectacular event to be seen from Earth. By way of comparison, the star that exploded to form M1, is some 6,200 light years from us, and the supernova explosion was bright enough to be seen during the day. So when these two stars do go supernova, the only objects brighter in the sky will be the Moon and the Sun, and even possibly just the Sun. But don’t worry about this happening any time soon. A few million years will still pass before this happens.
Happy hunting,
Alex.