Showing posts with label Molecular Cloud. Show all posts
Showing posts with label Molecular Cloud. Show all posts

Saturday, January 23, 2016

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.




Wednesday, January 20, 2016

To The Lagoon

I always keep a short list of deep sky objects I intend to visit in the near future. The Lagoon Nebula has always been on it and I was really looking forward to travelling there after my visit to both the Bug and Red Spider Nebulae.


Approaching the Lagoon Nebula from the galactic south, there are some objects that are worth visiting, namely the Open Clusters of NGC 6531 (aka Messier 21) and NGC 6530. Both clusters are relatively young and dense but still undergo expansion and the surroundings still have enough interstellar medium to continue star formation for quite some time. In fact, the not so distant Bug and Spider bear witness of how active the region still is. One red giant collapse here, one supernova there and you’ll have enough shockwaves ploughing through the interstellar medium and igniting hot dust cloud cores for the next generation of stars.

Speaking of stars: Of the brighter stars in those clusters there is one that has acted as a veritable beacon system in the past, a cornerstone of coreward expeditions and a magnet to cosmic explorers, tourists and – lately – pirates: The bright supergiant of Thor’s Eye. It has been labelled ‘Eye of the Beholder’, ‘Lagoon’s Jewel’ and also the ‘Maw of the Abyss’. Melodramatic for sure and everybody who has visited this system sure has different feelings about it!

I am somewhat biased towards the Eye. It is a type O star of more than 16 solar radii alright, but it does not have any celestials except a gas giant and a black hole. Yes, okay, a black hole but with FSD technology and ultra-resolution imaging systems it’s not that these are elusive stellar rarities anymore. Maybe I am a bit callous here but I can’t understand the hype about the system. However, word spread fast that the members of the Distant Worlds Expedition would pay this system both homage and a visit.

It was here that a wing of several pirates from god-knows-where waylaid unsuspecting explorers of the Distant Worlds Expedition not long ago. Casualties were light but rumours of these attacks spread faster than the speed of light in the scientific community, leading to an increase in the local travel advisory rating (which is generally a bad thing for unarmed exploration vessels).

However, there is another star system I would like to point out and that is LKHA 115. It is also embedded in the NGC 6530 cluster, but it has a total of three black holes, two of which are in close orbit around each other. The total mass of those three is a bit lower than that of the single one of Thor's Eye, granted, but the system is much more dynamical. If you have a graviton suite hooked up with your discovery scanner you might be able to pick up some gravitational waves from the two orbiting black holes. Good luck!

Now, the Lagoon Nebula, also known as Messier 8, is a very interesting region, because it is embedded in a much larger cloud of gas and dust in which, until recently, star formation took place. The result of this star formation is the Open Cluster NGC 6530, which lies directly at the Lagoon’s doorstep. It may have worked like this: Parts of the original bigger dust cloud must have collapsed, forming the young NGC 6530 cluster with its bright, hot stars. 



The solar winds of these new-born stars ‘burned away’ the remnants of the surrounding dust cloud of the complex. What is left is the star cluster on one side and the nebula we see today as the Lagoon Nebula on the other side. So the nebula is basically that part of the original cloud that did not collapse and commence star formation. That is why the Lagoon and NGC 6530 lie so close together: They are made of the same matter from the same cosmic cloud and thus the ‘Lagoon Complex’ bears great similarity to older star forming regions like the Orion Complex or the Carina Complex. The ‘Lagoon’ is just younger, an astronomical infant, so to say.

 

Leaving the Lagoon behind, the Distant Worlds flotilla soon set course for the next important waypoint, the Omega Nebula. As it happens, the Omega Nebula is also on my short list of 'things to visit' so I can't await arriving there and have a decent meet-up with some of my exploration pals.

Time to move on...

Sunday, November 15, 2015

Port Of Call

My fellow adventurers,
on November 14th, 3301 AD the AGS Intrepid finally called port at Irkutsk Capitol in the Alliance system of Alioth. After having been out in the Orion Spur and Perseus Arm for five and a half months the first session in the station was spent in the 'Dubai Lounge & Bar'. The second was spent waiting patiently in a queue at the Stellar Cartographics Exploration Data ATM.



The Pilgrim's Path Mission was declared a success, its prime mission statement of traversing the Orion Spur Shallows well beyond NGC 3199 was fulfilled. Along the way, many known and previously unknown stellar phenomena could be visited and explored in various degrees. These were (in order of visitation date):
- HIP 63835 (The 'Explorer's Graveyard')
- The Coalsack Dark Nebula
- Open Cluster NGC 3532
- Open Cluster NGC 3114
- Open Cluster Collinder (Col) 240
- Open Cluster NGC 3590
- The Statue of Liberty Nebula (NGC 3576)
- Open Cluster Collinder (Col) 228
- Open Cluster NGC 3324 & the Eta Carinae Solar System
- Open Cluster NGC 3293
- The Eta Carina Nebula (NGC 3372)
- Open Clusters Trumpler (Tr) 14 & 16
- The Seven Sapphires Cluster (Smojo Sector)
- NGC 3199 Wolf-Rayet Nebula
- Traversing the Far Orion Spur Shallows
- The Vela Ultima Molecular Complex (Hyuedau/Preou Thua Sectors)
- The Hyon Cluster (Hyuedau Sector)
- The Gloomgown Association (Phreia Phoe/Gludgou Sectors)
- The Skull and Crossbones Nebula (NGC 2467)
- Open Clusters Haffner (Haf) 18 & 19
- The Hyperion Cluster (Hypio Phoea Sector)
- Open Cluster NGC 2384
- Open Cluster NGC 2367
- Open Cluster NGC 2374
- Thor's Helmet (NGC 2359)
- Open Cluster Collinder (Col) 132
- VY Canis Maioris Solar System
- Vela Dark Region


Some statistics:
Departure date: May 30th, 3301 AD
Return date: November 14th, 3301 AD
Hull Status on return: 67%
Systems visited: 2,917
Distance travelled: ~73,000 LY
Rank achievement: Pioneer
Highest payout: 480,011 Credits
Coffee consumed: 6.48 Metric Tons


Next steps:
'After the trip is before the trip' as they say. The AGS Intrepid is being overhauled at the moment and I am turning my eyes on a ship that can withstand the rigors of space even better while also providing ample space (and protection) for deep space equipment and maybe the capacity to drop a ground vehicle. Yes, I am planning to go out there again but what I have in mind is a light exploration cruiser. The Alliance uses some to great effect. The 'Long Arm Program' is headed by several Anaconda-class vessels, and even some T-9 Heavy's, kitted especially to serve in deep and unknown space.


I guess I have to stock up my wallet for this a bit, though. Those biggies do not come cheap and that goes especially for an explorer trying to squeeze out every bit of range. Let's see how this turns out.

Thursday, November 12, 2015

The Lighthouse


'The circle is now complete!' I recall this quote from some entertainment Holovid, can’t remember which, but it was definitely Sci-Fi. Well, I guess the same applies to me and the Pilgrim’s Path. The Perseus Arm is rich in exploratory marvels. It still holds enough gas and dust to give birth to all the different types of stars an explorer could hope to see and, well, explore. That's the cycle of stellar life and death as I have mentioned before. Out there in the deep Perseus Arm you come across a stretch of space that is so rich in the younger, hotter types of stars and you struggle to find a suitable name for it; at least one that supercedes such flashy sector names like Gludgou or Ouchorrs.  

And speaking about circles, my voyage also finally comes around full circle: Yesterday evening I once again crossed that invisible line I once defined as the border between contemporary and 'creative' astronomy. 'NGC-Land', here I come. Finding names and imprinting them forever on some galaxy map is a thing of the past now. With full speed ahead I am nearing what in ancient times was called the Known World. For explorers it’s what you might call a return home. For seafarers of old, your homely shores await: Your astrometric computer stops struggling with Gludgou’s, Flyiah Eohn’s, Hyuedau’s or Smojo’s. Where stellar cartography seemingly ended at NGC 3199 way up 'north', it begins anew here and now where The Perseus Arm kisses the Orion Spur. Sorry for that bit of poetry, I couldn’t resist. But the scenery is this: Open clusters, nebulae and dust clouds have their respective catalogue entries listed, you see NGC’s, Col’s and IC’s again. Civilisation, you have me back! 


You also realize this when after months out in the deep, deep void you see a familiar shape unfold before the galactic horizon. Switch to infrared and you see mighty Barnard’s Loop. Switch to UV and you see bright young stars greeting you. 'Hey Barny', you think, 'I last saw you five months ago. How you’re doing old pal?' 
 I like to draw parallels to navigation and astronomy in ancient times. I have quite a few Holo Novels at home and even a few real paperback books. 'Barny’s Loop' is what must have been the beam of a lighthouse in familiar waters: Once you see it you know home is near. It’s a magnet, really. Inevitably it draws you nearer and nearer and in your guts (I already mentioned every explorer has his personal 'guts') you have this warm feeling that it’s a good thing. A welcoming light. Home, at least for a few days, before The Sea calls you again. 
It reminds me of some lines from an archaic poem, yet they are still true in the days of the Frame Shift Drive.


'They come forth from the darkness, and their sails
Gleam for a moment only in the blaze,
And eager faces, as the light unveils,
Gaze at the tower, and vanish while they gaze.'

And thus I give myself to my ship and my guts, and my nav courses bring me nearer and nearer home. And the lighthouse comes closer with every step.

Thursday, October 29, 2015

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'.

Wednesday, September 30, 2015

Patience, Young Padawan!


During my days at the Tau Ceti Naval Academy our instructors would often interrupt their lessons with the one and only question: 'What are the true virtues of a Space Pilot?' Hell, some even woke us up in the middle of the night (which were short anyway!) and asked us that. Although the answer was what must have been one of the Navy's best guarded secrets we always thought of things like bravery, loyalty, integrity or truthfulness. We were so young...



Now, right here in my 'AGS Intrepid' some 20,000 light years away from Tau Ceti I finally found the answer in a lockbox that was securely stowed away in some corner of my mind for all these years. The true virtue of any Space Pilot is patience. It's that simple. You see, space generally is not the flashy funky place full of speedy spacecraft, burning thrusters and glittering lasers and all that 'Space PR' stuff. No, most of the time it's empty, it's without sound and it's soul-crushingly boring. There can be some rare exceptions to this...


...some routine duties...



...but it all gets down to a lot of uneventful hours at the helm.


So for the last 6,000 light years I made my way through what I cynically called the 'Carina Suburbs': Uniformly looking space just like those prefab homes in an endless row where one looks like the other. I can confirm now, that M type stars make up more than 90% of all stars in the galaxy. Well, maybe it's even 107%, I don't know... What I know is I can confirm zero nebulae, zero giant stars, zero O-types and zero stellar remnants along the way, except for a one-in-a-million Neutron Star. This puts the explorer's mind to a test. Those brave souls that have flown through the 'Smoju' or 'Blia Euq' Sectors know exactly what I mean. The reasons for this I already mentioned. These regions of space are very old, most young stars went nova long ago and all interstellar gas has long been used up so there is hardly any star formation left. This makes the regions so 'plain'.
Here comes your space virtue: In a vast stretch of space where there are no significant 'beacons' standing out from all these stellar suburbs your patience is being put to a serious test. When I decided to do a traverse across the Orion Spur Shallows towards the Perseus Spiral Arm I was tempted more than often to just speed things up and do what you might call a stellar drive-by. After all the density of stars becomes significantly lower in the Shallows and this alone keeps telling you to 'go faster' just in order to be rid of it. 


This is explainable from a psychological point of view, because – sure! – we seek the unknown, which has to be amazing and shiny, right? Wrong. It's wrong, because even within M type star systems there are some rare finds. But the thing truly is to stay determined and keep looking. If you do, you can discover tiny terraformalble planets in close embrace of their M star, you can discover gas giants that do the same (and are therefore called 'Hot Jupiters' or 'Hot Neptunes') and there are even some Water Worlds with indigenous life lying in wait for the not-so-bored explorer.





Should I ever return to Tau Ceti (or even the Federation) I will pay the Academy a visit and write it a hundred times across the Forum walls: 'A Space Pilot's virtue is patience!'



'nuff said, time to move on. I have a vast star formation cluster waiting for me at the end of the rainbow.

Tuesday, September 15, 2015

The End Of The Rainbow

When you think the Eta Carina Nebula is a beautiful gem in space then the Wolf Rayet nebula of NGC 3199 plays in the same league. The nebula was once thought to be a ring nebula with a bright 'front' or 'shockwave' of gas, the result of intense stellar winds by a nearby Wolf Rayet star (HD 89358). Don't bother looking there, the star is at a completely different location for reasons unknown. It's not even in the line of sight from Sol. Sometimes I think 21st century astronomers were a drunken lot.


The nebula is not nearly as enormous as Eta Carina but it's still some good 80 light years wide. It also has considerably fewer massive stars around, suggesting that it's somewhat older in cosmic terms than the Carina. What is more interesting perhaps for the intrepid explorer is that when following the Orion Spur here, NGC 3199 seems to be the very last feature 21st century astronomers (yes, the drunken lot) could come up with. 


Beyond, the 'suburbs' begin again with seamingly monotonous space; or you head coreward from here and get the opportunity to see some spectacular star forming regions in the more dense Sagittarius Arm. However, once you fly through brilliantly named sectors like 'Bloo Dryiae' or 'Blia Euq' you get the picture.
The regions beyond NGC 3199 are also those where star density can become a problem at times. My good old Asp flies at 34 Light years and has so far laughed off any 'gaps' between stars but out here I find myself replotting courses or setting them manually more often. This is where I keep reminding me of the Mission Statement: Finding a traverse across the far Orion Spur Shallows and I think I'll get my work cut out for me.

Update: I left NGC 3199 well behind and finally found a system from where I will commence my traverse. I dubbed the system 'Hellsreach' because it boasts no less then nine celestial bodies with volcanic and/or magmatic activity that are nestled between a massive young B type star and its three orbiting protostars. I honestly don't know why I picked this system as my Waypoint Alpha. Maybe it's the desolate feeling of 'Don't go any further!' this system radiates.



Anyway, the primary is a scoopable so now it's time to plot courses for the great Far Orion Shallows Traverse. 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...