Sunday, June 28, 2015

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 20th 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!

Thursday, June 25, 2015

Oh Carina!

Okay, I have a problem. When exploring the unknown and covering distances of thousands of light years you start to speak in superlatives of the things you see. I mean, Black Holes, Supergiants, Nebula after Nebula? Planets with indigenous life? Not long ago, this was the stuff of legends and no wonder you start to choose the highest categories of words that come into your mind.

And here I am, having reached the Eta Carina Nebula; and there are no more superlatives left. 

I have described other things as 'amazingly beautiful', 'awe inspiring' and 'truly magnificient'. What else is there now for this jewel in space? It is like an arrangement of red, orange and dark curtains falling down, thus revealing its intriguing interior, which seems to be a small cosmos of its own.Eta Carina Nebula is the heart of the Carina Molecular Complex. Well, in fact it is the 'last' of multiple structures in the Complex, whereas other clusters and nebulae lie 'in front' of it when approaching from Sol (or Alioth in my case). But it is also the climax, the beautiful crescendo of a galactic cloud some thousand light years wide.

The nebula itself was once thought to be (at least in part) the product of ejected planetary material from a Wolf-Rayet star. There is no WR in the nebula, however, so maybe it already died many years ago. The death of stars is a common sight in and around as there are some Neutron Stars and also a couple of Black Holes in the vicinity. These violent deaths in the past may (or rather must) have contributed to the nebula's immense gas columns. These columns, like I said, seem like curtains to me and astronomers of old attributed several flashy names to them, like the Keyhole Nebula (which is indeed a substructure of Eta Carina Nebula so to say), the Homunculus Nebula and even a 'Finger of God'. Speaking of fingers, when you look at it from a distance the nebula looks like a hand, don't you think? A hand that was somehow blown into its shape by cosmic winds from 'bottom to top'. 

Astronomy and imagination don't lie that much apart sometimes...

All right, hands and death aside, there is also star formation that can be observed in and around the Carina structure, too. There are many T Tauri stars lying closely together and the occasional massive O type star, including the supermassive Eta Carinae system itself, already foreshadow the next wave of deaths that will occurr here. This in turn will once again enrich the interstellar medium for new stellar births. It all comes full circle here.With all this to discover the Eta Carina Nebula is a definite 'must' for any explorer going in this direction. For me, it's 'Sayonara Carina!' as there are even more superlatives out there on my way. I hope I will find the right words for them. 

Time to move on!

Tuesday, June 9, 2015

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 20th 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...

Wednesday, June 3, 2015

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.

Monday, June 1, 2015

The Explorer's Graveyard

Speaking of the 'doorstep' of inhabited space, both Musca Dark Region and the Coalsack sport some very interesting places to see. As I came across several of these, I decided I might as well share them with you, so here we go.

First of all, there is HIP 63835. Granted, it's still in the Wregoe Sector but I'd like to include it anyway. Dubbed the 'Explorer's Graveyard', it's truly worthy of having an entry of its own. This system seems to have claimed many lives and you can virtually feel all the wrecks drifting aimlessly in some unidentified signal source throughout the system. Still, the Graveyard is a very popular magnet for Explorers, despite the dangers lurking within. And here is why:

The star system's central body is a very young O-type Main Sequence star with more than 74 Solar masses and 14.55 Solar radii. This alone makes an astonishing sight when dropping out of Hyper. But what is more impressive still is the first of the three (!) Black Holes orbiting the central star at a mere 55 Light Seconds (LS), which is only a tenth of the distance between Sol and Earth. It has 15.5 Solar masses and an orbital period of (only) 1.2 standard days. I guess orbiting a star with more than 14.55 Solar radii in not much more than a day makes the BH quite fast. Luckily my FSD Drive didn't drop me into the Hole's Accretion Disk or Event Horizon, because that would have made my trip real quick (and fatal).

But HIP 63835 madness doesn't stop there. No!

Orbiting the central star at a mere 680 LS (Earth orbits Sol at appr. 500 LS) are two more Black Holes (6.4 and 3.7 Solar masses), interlocked in a mutual orbit at an unbelievable 4 LS! That's less than four times the distance between Earth and Luna!
And dancing dangerously close around them are no fewer than four Brown Dwarfs and two Class III Gas Giants, waiting to be eventually sucked into the Holes' black, gaping maw.

Interestingly, there's even a mineral-rich planet suitable for Terraforming on the twin Holes' dinner platter. Its characteristics DO look a bit odd but I guess Terraformers are little miracle machines anyway. A house with a view of the night sky would be fine.

I hope the Sirius Corporation doesn't get any funny ideas about this...

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...