I am the Alpha and the Omega

Where the Lagoon Nebula was already an eyecatcher, I was most eager to find out more about one of the jewels on my 'To Visit' list: The Omega Nebula, also named the Swan Nebula or just Messier 17. In fact, from the Lagoon you can already get your first glimpses of the Omega Nebula, a distant and darker hue of gas against the plane of the Milky Way. You will also see the bright, young stellar cluster of NGC 6618, which was born out of parts of the nebula in the not-so-distant past.

The Omega Nebula is thought to hold some 800 times the mass of Sol. That is no biggie for a nebula, mind you, but those parts of the Omega Complex that we don't see hold some 30,000 solar masses more. This makes the complex one of the most massive ones on our side of the galaxy; and it also gives you an idea about the complexity of those interstellar gas clouds. In fact, the complex is nearly identical in its makeup when compared to the Orion Complex in our immediate neighbourhood. We just see it at a different angle from Sol.

 

The area around the nebula is a so-called H-II region, a region dominated by ionized atomic gas. This ionization comes from the nearby cluster of massive, young stars, namely NGC 6618. Their radiation is so intense that it tears atoms apart and makes the surrounding gas heat up and 'shine'. So when we see the Omega Nebula, we only see an illuminated hotspot within a much bigger cloud of gas and dust. Again, it gives you an idea about the size of these interstellar cloud monsters.

When talking about the young star cluster of NGC 6618 we are talking about a former part of the Omega Complex that somehow collapsed and gave birth to a multitude of protostars (both T Tauri and Herbig Ae/Be stars) and young main sequence stars, including a few O types. They should now be in the process of using up the remains of the cloud core's gases and eventually drift away. For the interested explorer, there are quite a few very interesting objects to be surveyed here. The most massive stars seem to have collapsed already so there are quite a few neutron stars and black holes hidden in the cluster. Especially the stars of the PW2010 survey seem to hold most of them and they are awesome to behold and sometimes quite hazardous to navigate.

 

Scanning down all of the NGC's stars would obviously take a huge amount of time and would warrant an entire expedition in its own right, so I made a mental note on coming back at a later time. It's not like those stars are going anywhere soon, their expansion rate is estimated to be merely 12km per second.

A Tribute To Harlow

Yes, we know today that the Milky Way is a big place full of lights and wonders and that we start each and every exploration trip from a pretty normal, if not outright boring place in the galactic disc. But that was not always so. Back in the 20^th century the scientific community based their world models around only one galaxy in the entire universe and the firm belief that Sol was located in the very center. So far, so good, 'barbaric times' you might want to put forward as an argument. Looking back now, 1,300 years later, we allow ourselves to be that arrogant, but we omit the fact that science never was and will be a static thing. It belongs to the Frontier and the new Horizons we open up with each passing day and light year.

It is because of this that the first 'real' waypoint couldn't have been selected at a more ideal point. The Distant Worlds flotilla assembled at the planetary nebula named Shapley 1 (dubbed the Fine Ring Nebula, because from Sol we see a nearly perfect disc/ring). And it was that guy Harlow Shapley back in circa 1930 AD who through tireless observation and calculation deducted that the Milky Way had to be much bigger than it was thought back in the day, and he also found out that Sol was located at a dull spot near the fringe and not, as scientists believed, in the very center. Needless to say, he had a hard time and a Great Debate then about the fuss he created. Essentially, Shapley hadn't scratched at a pillar of the astronomical 'world' model, no, he just kicked it over.

Now, you might say 'Why is Shapley 1 so ideal as a first waypoint?' and I would answer 'Because from here we venture forth to show that the galaxy is a richer and bigger place.' Once again, we are at a threshold to commit ourselves to opening our eyes to the universe and to bring home a new idea of its vastness and beauty. 

 

I cannot think of a better and more symbolic place to start this endeavour...

A Sail On The Horizon

I had just settled for the night. It's hard to remind oneself that in this forever blackness of space the Human mind is still dependent on cycles of day and night. There are those people that keep asking what the must-haves for an exploration vessel are. Some say heat sinks are a must-have, some say auto-maintenance units. I highly recommend buying an alarm clock in one of those 'Shepard’s Famous Shops' in any space station, one that shows you it’s three o’clock in the afternoon or two o'clock in the morning. Time for a nap. It helps not getting mad.

 

I was still within the boundaries of the Vela, the constellation of the Sail. The Orion Spur Shallows lay behind me (for which I was very thankful) and I was eager to find out what was out here. The galactic south - I had found out on many occasions - always held some wonders in store. In ancient times there was just the big Argo Navis constellation in this part of the Milky Way. It was also one of the most important ones, because all ocean-sailing navigation techniques depended on some of the Navis' brightest stars. But when cataloguing the heavens became more and more sophisticated astronomers of old split the ancient Navis into the three constellations we know today:Carina (The Keel), Puppis (The Stern Deck) and Vela (The Sail). 

So I was dreaming of credits and sails when the autolab raised an alarm and woke me up again. I had left the ship 'on auto' and prepared some simple analyses and statistical comparisons before I wanted to set off again. There were also some issues with copying the newly acquired exploration data so I took an extra day just to be sure. 

After completing all its analyses the autolab confirmed what I already had in my guts. Experienced explorers always have something in their guts. They just need scientific methods to tell them what it is. Here there was an increase of interstellar medium density by 1,736% with an increase alone in metals by 6,104%. Most of the time, you have 0.1 to 10 atoms of 'stuff' per cm³ in interstellar space. 

And metals? Well, 'metals' in astronomy just means anything but hydrogen and helium and a significant increase in metals shows you that you have entered a region where many stars exploded in the past, blowing their heavy elements in jets and clouds into space. Parts of the region were so dense that not even thermic infrared radiation could penetrate the dust layers. Everything lying within these dark molecular structures was subject to speculation. There are theories, however, that propose a stellar nursery of sorts. Where the material density within the cloud increases beyond a certain threshold these dust 'cores' begin to collapse under their own gravity, forming protostars eventually. These protostars (T Tauri stars mostly) then accrete the rest of the dust cloud making it more and more translucent. I ran an infrared imagery and was relieved to see this theory underlined by a group of T Tauri stars within and on the border of the dust cloud. 

 

It was worth being disturbed in one’s sleep. Additional astrometric checks and the first incoming results from spectroscopic scans were encouraging. There were some rather dense groups of young and hot stars within what must once have been a planetary nebula, now nearly extinct. All in all the Molecular Cloud was estimated to be at least 800 LY across and some 150 LY deep. Quite a thing. So I created a data set and named it the 'Vela Ultima Cloud Complex'. There was plenty of time to study it a bit further...

... but first there was a nap to take. My alarm clock showed 04:37 a.m.

So I programmed the autolab on coffee at 09:30 and unfolded the bunk again.

Time to 'nap on'.

Remarkably Unremarkable

Soooo, for the best part of last week I crisscrossed the regions beyond the Eta Carina Nebula.

I made it downwards to -270 LY, climbed again through the ever present 'red' layer of Brown Dwarfs and Protostars and upwards to some 250 LY above the galactic plane, ever pushing forward towards my next Milestone of NGC 3199. In a nutshell, what can be found here is unlike anything I saw in my prior travels, which were rich in phenomena such as giant stars, star clusters, young OB star associations, the occasional nebula and also multiple Neutron Stars and even some Black Holes.

I don't know how else I could describe the area beyond Eta Carina than being 'remarkably unremarkable'. With the huge and beautiful Eta Carina Nebula behind, all signs of ancient 20^th century astronomy seem to end. There are no more 2MASS, CPD, HIP or HD denominations, no COL star clusters from the Collinder Catalogue. Beyond Eta Carina, it seems, astronomy once upon a time must have ended. From here, one could argue, astronomy blends with your own imagination and beliefs.

There is a scientific reason, of course, for this. The regions between the Spiral Arms of Sagittarius and Perseus are very old ones when you look at the stars' age. Here, between the bright Spiral Arms, most interstellar gas was used up long ago and thus no or barely any star formation takes place these days (astronomically speaking). Even B type stars and protostars are very rare out here. The lack of giant stars complements this as their far shorter lifespans compared to main sequence stars means they also died in the distant past. Essentially, all you see is vast stretches of K and M stars dotted with Fs, Gs and Ls. The result drawn on a map can be described as one of those homogenic metropolitan suburbs back home where one house looks like the other and where one lawn had the exact same dimensions and colours as the ones left and right. Hell, I was even tempted to call them the Carina Suburbs but in the end that might just have been a bit nasty, wouldn't it?

Still, there are sights to be seen; but you have to either look specifically for them or you just chance upon them in your travels. Older stars mean more room for terraformable planets and even some rare places where life already did evolve.

There is also one particular phenomenon I would like to present a bit closer: Nestled deep within the brilliantly named 'Smojo' sector and sitting right on top of the Brown Dwarf belt lies the 'core' of what might be an Open Star Cluster. At least, the presence of seven closely associated B stars with the exact same spectral class (B0 VZ) and some Protostars around might indicate that they formed in the same cloud complex (which is now extinct due to star formation and ionization). Admittedly, that's where imagination and astronomy blend together. But we are humans, right? We are always obsessed with 'seeing things' where science tells us there is nothing to be seen. Put a Smiley in here, HAL.

Now, I have dubbed the cluster the 'Seven Sapphires'. Of course, further investigations would be necessary to determine this Cluster's age and structure but at least there is something out of the ordinary to report home. Ah yes, the cluster is also a quite lively place as there are numerous Water Worlds and Gas Giants with ammonia- or water-based life around, so this might just be the 'stopover' for Space Trucker generations to come. Real estate investments, anybody?

2,000 and some LY  to go to NGC 3199. Time to move on!

Clusters and Molecules

Another week, another peek!

It's really hard not to give in to temptation and divert to that seemingly unique jewel you have spotted on your Galaxy Map. I did it a couple of times, going here, going there. Most of the time, it left me baffled about the beauty of the 'out here'. I remembered some of my Astrophysics lessons back at Tau Ceti and I realised that all these space phenomena are connected in a way. So even that far and remote place is just a puzzle piece of some greater thing. 

In my case, it's the so-called Carina Molecular Cloud (CMC) and it's known to be one of the biggest structures in the known galaxy, spanning hundreds of Lightyears in diameter. Although the Carina Nebula is still some 2,500 Light Years out, I am already moving through its associated complex, full of Open Star Clusters, younger regions of star formation (like the Carina OB1 and OB2 associations) and also some silent witnesses of stellar extinction, like the occasional Neutron Star or White Dwarf.

Speaking about Open Star Clusters, it is generally assumed that they all formed out of the CMC, although not all simultaneously. These clusters are generally some ten to fifty LY across and densely packed with stars, either in the form of a clump or more of a string. Some of their stars were so short-lived however, that they already ceased hydrogen fusion or even went supernova, explaining the occasional Neutron Star, Black Hole or even Wolf-Rayet star in those clusters. The Clusters' cores mainly consist of the more younger types of stars like O, B and also A types, and they can be easily spotted on the Galaxy Map by setting the star type filters accordingly. Here is an example of the larger Open Cluster of NGC 3590:

If ancient archives are to be believed, it took the 'Early Tech' astronomers of the 20^th century quite some time to realise that most prominent nebulae are in fact only the 'hot spots' within the bigger Molecular Clouds. The Orion Nebula is a perfect example for this, and so is the Eta Carina Nebula. In ancient pre-spaceflight times, however, most nebulae were seen as separate entities. The bigger picture is, simply put, that Molecular Clouds are hard to detect, because they are cool and hence emitt barely any visible light. But when a star goes nova or supernova the ejected stellar material compresses the surrounding dark clouds, promoting star formation through gravitational collapse of the cloud. Young stars in turn emitt heavy energetic radiation that ionizes the interstellar medium and thus makes it 'shine' in different colours, depending on its chemical components. Ionized Hydrogen is most prominent, shedding the characteristic red light as can be seen in the region's magnificient Eta Carina and Statue of Liberty Nebulae (which can be seen below).

So for the non-poethic or non-aesthetic people, this beautiful nebula is just a relatively small patch of a Molecular Cloud made visible by some young stars' heavy radiation, much like an area of a green park lit by a lantern. The darker reaches remain obscure and, well, makes one itchy to redirect the Nav Computer and to go there and find out, what's there to be found. To honour this most endeavoring attitude, I have compiled a small collage of sights and places:

Now Eta Carinae is waiting. Time to get a close-up look at her beauty. Time to move on...

The not so bad Badlands

Eastward Ho!

For the last two days I navigated a route towards the Galaxy's trailing direction and crossed the Orion Spur Badlands, which are not much more than a band of Brown Dwarfs and T Tauri-type stars stretching on for what must be forever. My first destination was the NGC 3532 Open Cluster in the Carina Complex (dubbed the 'Black Arrow Cluster' for some reason) but after having to re-route several times just in order to get to a stellar filling station I just switched my goal to 'Get the heck out of here!'

Yes! Red means no fuel...

The Badlands aren't just bad, however. There are many interesting places to see and quite some giant stars to bump into as well and NGC 3532 lies nestled in these supposedly bad lands as well. It is supposed to be one of the earliest star clusters that was observed with Earth's first and ancient spaceborne telescopes at all so I figured it might still be worth a visit, despite all those Brwon Dwarfs prowling on the way.

Ah! As an aside, I urgently suggest to use your 'View by Stellar Class' filter on the Galaxy Map from time to time, since it facilitates a general overview of your surroundings AND provides you with info on the more reclusive types of phenomena as well, like Wolf-Rayet Stars and White Dwarfs. Do it every 100 LY or somesuch and you'll get the picture.

Speaking about pictures, there's some info to be shared if you want to venture into that region; and what makes it better than having a peek preview of what's out there?

Beta Muscae – Explorers will find a Black Hole and a Neutron Star here.

HR 4499 – We have a G-type Supergiant with nearly 37 Solar radii being orbited by a companion star (which is not unusual). For those of you unfamiliar with stellar dimensions, just imagine Earth being here on its regular orbit and then take a look from an imagined El Capitan summit in Yosemite National Park. 

Amazing, is it not?

245 G. Carinae – A B-type subgiant, where apparently hydrogen fusion stopped already, and it's being orbited by a Neutron Star, bearing witness, that a star has died here in the past already. 'Soon' it will be the main star's turn...

HD 102773 – The most obvious thing here are two Black Holes, hungrily sucking the lifeblood from this star system. The strong gravitational lens effect of the Holes is very impressive and one might think there's only destructive hostility to be found here. However, there is life on the Gas Giant orbiting one of the numerous Y-type Brown Dwarfs. Considering these and the system's B-type main star one can only wonder what kind of water-based life can exist here. Due to the apparent heavy radiation and solar winds impairing the magnetic field of the Gas Giant it is to be suspected that it's some kind of radioplankton deriving its energy from molecular ionization rocesses. But I'm an Explorer, not a Xenobiologist...

HD 303310 – An M-type Supergiant at 33 Solar radii. The star can be viewed as one of the representatives of Giant-class stars in the NGC 3532 Cluster. Have a look around and you can glimpse quite a few of them!

Upsilon Carinae – Woops! Giant Star Madness! This system is awesome: Two A-type Supergiants in a close orbit of only 2,300 LS. Luckily, my approach vector didn't involve getting 'sandwiched' between the two. But still they are some heavy dudes, one having a radius of 77.5 Solar radii and the other even tops this at a whooping 218 Solar radii. You have to look from a viewpoint on an imagined Earth orbiting Sol at 500 LS to get the picture.

Right? Imagine the night skyline of New York or Dubai against the backdrop of these two stellar monsters...

HD 92072 – There are two Neutron Stars to be found here orbiting an F-type Bright Giant. Quite a prize, to be sure, but in picture terms pretty unremarkable, to be honest.

Passing HD 92072 we are approaching the rim of the NGC 3532 Open Cluster. Of course, it was not a thorough survey of the entire cluster. There are at least 150 stars directly associated with it and there may be more jewels on the left and right. But that will be another journey, someday.

Time to move on. There is still much distance to be covered and I plan to pay NGC 3114 a visit, another Open Cluster en route to the Eta Carinae Nebula.

To the crossroads, once more...

I returned three days ago from a two-months trip to the NGC 7822 Stellar Nursery area, mapping out YSOs, Black Holes and Neutron Stars. It took me two days of trading in a cramped T-7 to realize (again) that I don't belong here. Busy trade lanes full of traffic, comms chatter, wannabe pirates and the omnipresent systems' police. I got wanderlust... again. I sold my Beryllium (for the gazillionth time), gave the traffic warden some bucks for a mug of coffee and told him to mothball my Space Mule and went to the Stellar Cartographics Bulletin Board. It didn't take long to find a secondary entry, on behalf of a privately funded operation, asking for aid in mapping out the edges of some of the Milky Ways' spiral arms. What followed was a short comms exchange with the operation's Commander, and then things were set: It would take a decent amount of time but should be worth the stretch. StellCart would buy the exploration data as usual but would leave all other mapping rights to the operation. A more perfect stage couldn't be asked for...

So I went out in my 32 LY Asp Explorer and headed towards the Musca Dark Region and the Coalsack Dark Nebula. I like to see the Coalsack as a crossroads of sorts, because from there you can basically go further coreward, towards the Pipe Dark Nebula and, further on, the Lagoon Nebula; or you might go in the galaxy's trailing direction, where eventually you will find the Eta Carina Nebula and get to the rim of the Sagittarius Arm of the Milky Way.

Both, Musca Dark Region and the Coalsack are ideal for novice Explorers as they basically lie at the doorstep of inhabited space and are easy to navigate and quite dense with stars. Musca is a place filled with many, many brown dwarfs (where you cannot scoop fuel) but also patches of main sequence stars with the occasional sub-giant or (super-)giant star. Ah yes, and quite a few of the very young O and B type stars, which are generally hunted for their Black Holes and Neutron Stars they might contain.

Approaching the Coalsack, the stretches of brown dwarfs get thinner and give way to the more 'regular' variety of stars. Star density is still more than enough to navigate here and quite a few stars have terrestial planets suitable for Terraforming or even boast an intact ecology already teeming with life. And then of course there is the Dark Nebula of the Coalsack itself. It's a dark and beautiful jewel, especially when viewed with the Milky Way as background. Make sure to shoot some pictures out here for a postcard for your loved ones at home!

All of this presents many opportunities for the up-and-coming Explorer to hone his navigational skills and get a grip on the different types of stars and stellar bodies (yes, there are quite a few of them): What's a TT-star and what's a T-star? What's an A1 III and what's a Y5 V? Where do I find habitable planets? Where do I find planets rich in minerals? After some time, you'll get the hang of it, I'm sure.

Time to move on...