LMC & SMC
The Large and Small Magellanic Clouds (LMC & SMC) are staples of the extreme southern sky residing down at roughtly Declination -70 degrees. That puts them really close to the south celestial pole making them nearly impossible to see unless you’re below the equator, so you know I was going to make them a priority on this trip.
The problem was that both of these things were starting the night low to the horizon or below the horizon so I had to wait until later in the trip and late into the night before they would be high enough to image. No big deal though, I was already resigned to pulling some all-nighters on this trip.
As I write this, the main scope is in the middle of shooting a 12-panel mosaic of the entire LMC which, if it works out is going to be a spectacular (and large) image of 28,000 x 25,000 pixels with exquisite detail you can really zoom in on.
Last week however, I zoomed in and shot the ‘big star’ of the LMC: the Tarantula Nebula (NGC 2070) and what a wonderful, wacky target this is!
It’s a Rental
I had actually shot this once before using a commercial online southern-hemisphere telescope that I subscribe to but couldn’t really afford to get a large data set and my processing skills back then weren’t nearly as good. Here’s what that looked like:
I mean, it’s good enough to tell what’s there and it’s a bit wider of a field than I get with my rig but I thought the color was a little weird; maybe I should go back and reprocess this… Anyway,
I gave my new version of this a pretty “deep soak” with almost 6 hours integration time in Red, Green, Blue and Hydrogen using 3 minute exposures on the colors and 4 minutes for the hydrogen stack.
Processing was super easy and this thing just came right up and looked great from the get go!
The Tarantula Nebula in the Large Magellanic Cloud. (Click on the image to open a bigger version)
As I was working on this image I was again struck about what a unique kind of nebula it is, and it’s surrounded by all these crazy ‘bubbles’ floating in the adjacent space (close-ups later).
Cloud Brain
The Large and Small Magellanic Clouds are not ‘clouds’ at all, but appeared that way to Ferdinand Magellan in 1519 while he was on his three year, around the world voyage in which he would have to traverse down below Africa and South America which would have gotten him deep into the Southern Hemisphere. He saw these two ‘clouds’ in the extreme south and when he got back he reported them to the ’astronomers of the day’ and now they carry his name.
We know now that these ‘clouds’ are actually dwarf galaxies associated with, but external from the Milky Way. For the longest time they were considered to be ‘captured’ by the immense combined gravity of the stars in the Milky Way but lately there’s some doubt about that since they seem to be moving too fast to be captured; it’s a developing story.
Dwarf galaxies are common around large spiral galaxies, with our nearest neighbor the Andromeda Galaxy having somewhere around 18 dwarf galaxies associated with it and the Milky Way is in for around 14 last I checked.
Dwarf Galaxy NGC 205 orbiting around the Andromeda Galaxy
So the LMC is the Milky Way’s equivalent to NGC 205 in Andromeda.
The LMC is about 180,000 light-years from the Milky Way which is a decent distance, but nowhere near the distance to our nearest neighbor Andromeda at 2.3 million light-years so it’s considered very much a part of the Milky Way’s general group.
Since it’s a galaxy in it’s own right (dwarfs have billions to tens of billions of stars whereas full-fledged galaxies have hundreds of billions of stars) it has a lot of the same large scale features as big galaxies, it’s just they seem to look weird.
The Big Taranny
The actual Tarantula Nebula is a truly vast area of star formation out of immense clouds of gas and dust.
Closeup of the Tarantula Nebula’s star forming region
Buried deep in the heart of this thing is the star cluster R136 which has some exceptionally massive and bright stars putting out all the radiation needed to light this thing up. The Tarantula is probably the biggest area of star-forming nebula in all of the Local Group of Galaxies (Milky Way, Andromeda, and M33 in Triangulum) although there might be an area of M33 that rivals it.
The star-forming region in M33 that rivals the Tarantula.
The immenseness of the Tarantula can be appreciated this way–one of the most famous and large star-forming nebulas near us is the Great Orion Nebula which is about 1500 light-years away and just visible to the naked eye if you know where to look, in the area of Orion’s sword.
If the Tarantula Nebula was where Orion is, it would take up half the sky and would be bright enough to cast a shadow!
A Bit of the bubbly
Once you get over being awestruck by the Tarantula, you look around the photo and there is all these cool little bubbly things scattered all over.
That blue thing looks like a spaceship to me, but it’s probably as big as the whole solar system!
The Tarantula is Supernova, not bossa
Every now and then, a really big star reaches the end of it’s life and has no choice but to blow itself up like some geriatric cosmic suicide bomber, scattering heavy elements like carbon, nitrogen, oxygen, and iron it’s been brewing up in its core for the last however many billion years throughout the galaxy. It’s predicted that roughly once every thousand years or so you’ll get a supernova explosion in any given standard galaxy.
In the Milky Way there was a famous one that happened on July 4th, 1054 recorded by the Chinese (and whoever was living in the southwest US at the time) and then another one in 1604, which is referred to as “Kepler’s Supernova”. Unfortunately the telescope didn’t get invented until around 1610 so scientists have been itching to study a supernova with real scientific equipment and on February 23rd 1987 the light (and a blast of neutrino particles) from the supernova explosion in the outskirts of the Tarantula Nebula, which had been traveling in space for 168,000 years reached the Earth and scientists had their first nearby supernova to study.
The Hubble Space Telescope came online in 1990 and has made regular observations of SN1987A giving scientists lots of clear data on what’s going on there now.
The location of Supernova 1987A in the LMC, near the Tarantula Nebula
The LMC 12-panel mosaic will be my final big astrophotographic project here in Namibia and I’m cramming to get all the panels taken (@ 2hr 45min exposure per panel) before getting stomped on by moonlight from the approaching full moon phase and having to shut it all down.
The organization of the 12 panels in the Mosaic of the LMC project
I’m going to try and rough-process the data before I leave Namibia to make sure that all the panels will mesh properly and I can be sure that I won’t have to reshoot any of them which I could potentially do in a pinch super late at night. At the end of tonight I’ll have 6 + panels done and that’s going to tell me a lot about how this is going.
Carpe Noctem!
Bill Gwynne
September 5th, 2024