Saturday, 23 January 2016

M37

Charles Messier's 37th object is the brightest stellar cluster of the constellation of Auriga, already visible to the naked eye under a really dark sky. The odd thing about it is that it's a fairly old cluster (age estimated from 400 to 550 million years) but that it's still incredibly rich and compact. In fact, it contains roughly 500 members of which there are at least a dozen red giant stars (one of them really stands out and is clearly visible on my sketch) and that is quite exceptional for such a cluster. Then again, it lies at a distance of 4.500 lightyears in exactly the opposite direction from the centre of our galaxy, around which it orbits with a period of 219 million years. 

As I told you before, these rich open clusters are probably the biggest challenge for us, astronomical sketchers, simply because there are so many stars to draw that they'll push your patience and perseverance to the limit. Many fellow sketchers therefore give up, only draw the most important stars and then fill out the rest with a large number of random dots. But having been a contrarian all of my life, I didn't want to give up so easily and I can assure you that every single star on this drawing was in fact observed and confirmed with my own eyes before entrusting it to paper. How long did it take to finish the sketch? I guess about 2 or 2,5 hours. Plus twice as much behind the computer because the digital elaboration of my observations is in fact the most important part of my work. 

In the end I'm quite pleased with the result but now I wish I had made the cluster a tad brighter and had enhanced the red colour of its big central star a bit more. But hey... I'm not perfect. I'm sure that after seeing this many of you'll want to grab their binoculars or telescopes to discover, or rediscover, this stunning cluster next time the sky's clear. And then I'll be happy and consider that I've succeeded in my mission, i.e. to increase everyone's appetite to take a better look at the heavens.


Wednesday, 20 January 2016

M45, the Pleiades

The Pleiades were the seven daughters of Atlas, the giant of Greek mythology who carried the Earth on his shoulders. Zeus attached them to the sky so they could escape ruthless Orion who was set to hunt them down and kill them. In the winter sky you can still see Orion hopelessly chasing them towards the west, without ever catching them.

Astronomically speaking, the Pleiades are the brightest, the most famous and probably also the closest of all star clusters, with a distance currently estimated at around 440 lightyears. The main stars are still incredibly hot but with an age of over 100.000 years they've outgrown their "baby star" status and are ready to start their voyage through our galaxy. Calculations have shown that the cluster will be completely dispersed by interstellar gravitational forces within the next 250.000 years. Curiously enough, we can still observe a lot of nebulosity around the main stars and for a long time scientists have held the belief that this was dust and gas left over from the stars' birth. Recent analysis however, found that the stars are indeed too old for that and that the original gas and dust from their birth has already dissolved into space. It is therefore believed that the cluster is just coincidentally passing through a very dusty part of our galaxy. The fierce heat of these young stars reflects on the dark dustclouds and makes them visible to us. 

The best way to observe this cluster is... the naked eye. Just look up to the south on a winter's evening and you can't miss them. Also an ordinary pair of field binoculars (a 7x50 or 10x50 would do perfectly) will yield an amazing view. With my 24x100 binoculars, the magnification was a bit exaggerated to my taste. The more you increase magnification, the more you're looking "through" a cluster. But the bright nebulosity surely made up for that.



 

Tuesday, 19 January 2016

NGC246, the Skull Nebula

People invent the strangest names for the objects they find in the sky. I've already talked about the Monkey Head and Thor's Helmet (without even mentioning the Pac Man nebula - yes... it exists!!!), and today I'd like you to take a look at the Skull. At times I'm wondering if Wes Craven's still alive and is currently employed as a senior consultant in the international naming committee for astronomical objects. But when you take a good look at it, it does seem to resemble a human skull, doesn't it? Its central star is a white dwarf and actually one of the hottest known, with a surface temperature of over 200.000 degrees Celcius. It also shows interaction with the interstellar space around it since its western rim (top left on my sketch) is being torn apart by something unknown. The entire nebula compex also appears to move in that direction as well. You can find it in the vast but obscure constellation of Cetus - the whale - as it drifts some 1.600 lightyears away in a poorly populated part of our galaxy. Note that the other stars visible "inside" the nebula are in reality much closer to us.

This is the last drawing I've made with my good old home-built 18" Dobsonian telescope before I sold it (with pain in my heart) to partly fund my new 18" binoscope project. The nebula's fainter than you would expect for its 8th magnitude. That's because it's fairly large for a planetary nebula, twice as big as the famous ring nebula for example, and therefore its light is spread over a much greater surface. But at 85x and with an OIII narrowband filter it already showed remarkable detail.

Thursday, 14 January 2016

Comet Catalina C/2013 US10

When I was talking about comets in my previous post, I actually had this beauty in mind. But in order to see it, you either have to stay up late of wake up very early. Since I hate getting out of bed early and with bad weather forecast for the next couple of days, yesterday evening was going to be now or never if I ever wanted to have a go at this bright and interesting comet. I live about a 25-min drive away from my observation spot in the mountains and left home at 23:45 with Arcturus and the big dipper rising nicely in the northeastern sky. But when I finally arrived... the whole sky had clouded up, apart from a small hole in Orion. I could've died from agony and desperation right there! What had I done to deserve such a cruel fate? I had already seen so many stunning pictures of Catalina and read dozens of enthusiastic observation reports but alas, I felt that I was never going to see it with my own eyes. There was again a lot of wind and I was trying to find out whether the clouds were moving or not and if that hole would perhaps be so kind as to move to the other side of the sky. The clouds were indeed racing along, but for some strange reason the hole remained fixed in Orion and Taurus. I decided to wait 10 minutes and see what would happen next. I had driven all the way up anyway so 10 minutes wouldn't hurt. The hole refused to move but became slightly larger. Suddenly I saw Jupiter appearing through the clouds. Hmmm... perhaps I should wait a bit more. You never know, the gods might turn to my favour. Then, every once and a while, I saw the 4 main stars of the big dipper piercing through as well. The clouds were becoming thinner and slowly... very slowly... a hole appeared right above my head and started expanding towards the tail of the dipper. It seemed to last forever before finally the comet became visible (in reality it was about an hour later) and I managed to make this sketch. The clouds didn't move far away though and every now and then they covered the comet again. In the end a long veil of thin clouds established itself right in front of the comet, growing rapidly and eventually making any observation impossible. But fortunately I've been granted a reasonably fair view for 10 to 15 minutes and I'm extremely grateful for that. When I arrived I first thought that that would be the end and that the rain front had arrived earlier than predicted. But in the end my patience and determination paid off and I won't have regret that I never had the chance to see beautiful Catalina. So... NEVER DESPAIR! :-) 




 

Wednesday, 13 January 2016

Comet PANSTARRS 2013/X1

Comets are very peculiar objects. In fact, they're nothing more but large, dirty snowballs that follow very strange orbits around our sun. Most of them don't even have a fixed orbit at all. They come to us from the edge of our solar system, make a swift pass near the sun and then disappear into the depths of space again forever. As they approach the sun, the radiation and solar wind make the ice and dust evaporate, creating the well-known tails. Currently we have registered over 5.000 comets but scientists guess that the number of comets hiding in the so-called Oort cloud, a suspected cloud of icy bodies at the theoretical edge of our solar system and even far into interstellar space, would reach 1 trillion. 

On average there's a comet visible to the naked eye roughly once a year, but most of them won't blow you out of your socks. They're just small and incredibly faint blobs in the sky. The Panstarrs comet which is currently transiting our evening skies and became the subject of this drawing, can only be seen with a good pair of binoculars under a dark sky. But every once and a while comets do make a lasting impression. The most famous one is of course Halley's comet which pays us a visit once every 75 years and is due to return in... 2061. As I remember, its appearance in 1986 was a bit disappointing but let's hope that our children'll have a better opportunity to see it.

Comets are also responsible for a phenomenon that's probably even more spectacular. Their tail leaves a long trail behind of dust and rocky particles. When the Earth subsequently passes through this trail, the particles fall into our atmosphere and burn up in a big flash. You've guessed it! They cause the great meteor showers that we can see every year! The most famous of those are the Perseids which reach their peak around the 12th of August and are debris of the comet Swift-Tuttle. But also other meteo showers can be quite spectacular such as the Leonids, Geminids and Quadrantids. During these showers it's easily possible to see a meteor - popularly named a "falling star" - every minute, or sometimes even more.  

During my observation of Panstarrs I immediately noticed its slightly elongated form, but I couldn't make out a real tail. Also its small but bright nucleus really stood out. Unfortunately there was a lot of wind yesterday which made the observation difficult and if that wasn't bad enough also the local football team decided to practice. The football field's located about a mile off and twohundred metres down in the valley but the bright lights still managed to spoil my southern sky. But here it is...

Monday, 11 January 2016

NGC2359, Thor's Helmet

The sky is full of ancient mythology. Our constellation of Orion, the hunter or soldier, was to the ancient Egyptians part of the constellation of Sah, the god of the heavens and father of all the other gods. The three stars we know today as Orion's belt were to the Egyptians Sah's eyes and nose. To the Aztecs the same three stars represented Mamalhuaztli, the sticks that lit the new fire at the beginning of their calendar. The Chinese used to call them Shen, meaning "three stars" and they were part of the chinese zodiac. The Vikings on the other hand saw a distaff in them, which was used by the godess Frigg. 

Much of this mythology is now lost, apart from the official designations of the modern constellations which still refer to their Greek-Roman origin. But here and there we find an exception. One of them is this spectacular nebula called "Thor's Helmet". In my telescope I rather saw it upside down, but it doesn't take too much imagination to see a Germanic helmet in it. It's almost 12.000 lightyears distant but its gigantic central star is so incredibly hot that it heats up the nebula to the extent that to us it's already visible in a good pair of binoculars. It is believed that this central star is in fact in a pre-supernova stage and that one day it will die in an explosion of biblical proportions. The gas bubble around it, 30 lightyears across, is expanding at a rate varying between 10 to 30 km/s, blown up by the central star's radiation. So looking at the heavens not only tells us something about the origins of the stars, such as the baby stars in the Monkey Head nebula of which I told you in another post, but also about their end. 

My drawing was a fairly old one which I've recently completely re-edited using my new elaboration secrets and skills. It's one of my favourites and I hope that you'll appreciate the way in which I've drawn the stars and their subtle colour owing to the use of a nebula filter, the varying brightness of the background and the delicate filaments of the nebula. 




Friday, 8 January 2016

Our Moon

The Moon is our only natural satellite and it's one of the largest moons in the entire solar system. Its diameter is 3500km, or over one quarter of the Earth's diameter and much bigger than dwarf planet Pluto (just over 2.300km). It's much heavier than the latter too, over 5,5 times as heavy to be precise. Therefore our Moon is also one of the densest moons in the solar system, surpassed only by Jupiter's Io. It's believed to have formed shortly after the formation of Earth, approximately 4,5 billion years ago. One of the odd things about it is that it always shows us the same face. The near side, with its prominent "seas" of dark volcanic material, is also quite different than its far side which is mostly covered in impact craters. Although it looks very bright in the night's sky, its surface is actually as dark as worn asphalt.  

Next to the Sun the Moon has been the subject of study and worship since the dawn of civilisation. The Babylonians had already calculated a calendar to predict solar and lunar eclipses! But it was not until Galileo and his telescope that its true wasteland nature with its mountains and craters became known. Actually, during the Middle Ages people believed that its surface was perfectly smooth! Even today many people endow the Moon with magical powers and refer to the tides as proof of the effect that the Moon exerts on us all. The gravitational pull which creates the tides is however incredibly small, explaining why lakes or even the entire Mediterranean Sea don't have any tides at all (or very small ones). Several studies have in fact demonstrated that there is absolutely no correlation between a person's state of mind, the number of accidents or crimes or a person's character and the Moon whatsoever. 

Most astronomers don't really like the Moon at all. That's because even a small crescent Moon already reflects so much sunlight that it seriously impairs the observation of dimmer nightly objects. Yes, I have to admit it, I'm one of them and usually keep my telescope or binoculars locked up when the Moon's around. But some time ago I made an exception, under the influence of my fellow astronomy artists who publish some amazing works of art featuring the Moon's surface every month. So I just had to have a go at it as well and frankly, for being a first time ever, I'm more than pleased with the result. Especially creating the right colour effect proved to be tricky. I also tried to reflect the two halos created by my not very well aligned binoculars in the hazy summer atmosphere. Yes... this is more or less how I saw it.


Thursday, 7 January 2016

NGC2174, the Monkey Head nebula

You may find it odd that I want to publish a sketch of this unknown nebula as one of the first posts on this blog. Let's say that I want to rectify a big injustice. In all honesty, I have to plead guilty as well. I can count the times that I've visited this nebula on the fingers of one hand, even though it has all that it takes to be an all-time favourite: it's very easy to find, just south of ├Ęta Geminorum, it's bright enough to be observed in nearly every telescope and if you take a good look it easily reveals a myriad of filaments and details. And to top it off it has a funny nickname derived from its particular shape. So what more do you want?

But first, let me tell you something more about this peculiar object. The Monkey Head nebula is an enormous cloud of gas (mostly hydrogen) and dust heated up by incredibly hot and young stars within its heart to the point that it begins to emit light itself. In fact, this nebula is a gigantic star nursery! The light and winds from the newly born stars disperse the gas clouds in which they were formed and in the next millions of years these stars will leave the nursery to find their own way in the universe. It's perhaps not as famous as other nebulas in which stars are born such as the Orion or Lagoon nebulas, but nevertheless it's spectacular in its own right. It's 6.400 lightyears away from us (much further than the Orion nebula at 1.340 lightyears) and covers an area in the sky almost as large as the disk of the full moon. But unfortunately it's too faint for the naked eye so don't get overexcited. Please also note that the bright star at the centre of the nebula doesn't belong to the nebula at all but that it's a lot closer to us (994 lightyears). So you see that looking at the night's sky can be very deceiving. Similarly, the stars that form the various constellations have in reality nothing to do with each other and may often be thousands of lightyears apart. A popular example of this are the three stars of Orion's belt. In our sky they really look to belong with each other. In reality however, the left star is 817 lightyears away, the right one 916 lightyears, but the middle one... 1.976 lightyears!

For my drawing I used UHC filters which block most of the light, apart from the specific frequencies emitted by the nebula. This makes the background darker and also the stars, which emit light in all frequencies, look a lot fainter. This, however, creates a lot more contrast with the nebula and therefore it becomes visible more easily. The moment it entered the field of view of my binoculars it immediately leaped out at me. When looking more closely in my Nexus 100 at 24x, several details became easily visible, such as the "eyes" and "mouth" of the monkey's head. 

I sincerely hope that this post may incite others to visit this nebula too. It truly deserves a bit more attention.




Wednesday, 6 January 2016

NGC869-884, the sparkling double cluster in Perseus

When you take out your camper bed in autumn (don't forget that warm blanket and a hot cup of tea), look to the east. You will easily notice the constellation of Cassiopeia, which doesn't really look like the old queen from Greek mythology but rather like a bright, slanted W. Now if you take the left lower point of the "W" and go down a little bit, you will notice that there's a faint little patch, at first not that easy to see with the naked eye. Take your ordinary 10x50 binoculars and point at it. Go on! It'll make your jaw drop! 

Here's my impression with my somewhat bigger 100mm astronomical binoculars and a couple of 8mm TeleVue Delos eyepieces (resulting magnification 63x):

 
What you see are two open clusters of stars which lie at a distance of a whopping 7.500 lightyears, meaning that light, with its formidable speed, needs 7.500 years to travel from those clusters to Earth. The term "open cluster" means that the individual stars in it can be resolved quite easily, contrary to a "globular cluster" which is much denser and can only be resolved with larger telescopes. Open clusters also lie within our galaxy whereas globular ones are in fact a kind of "mini galaxies" which accompany our own. These particular open clusters are also still very young, with their age estimated at less than 13 million years. In comparison, the famous Pleiades, also still young, have an estimated age ranging from 75 to 150 million years. Therefore the thousands of stars in these clusters are incredibly hot and it is very unlikely that we'll find extraterrestrial life there because planets probably still haven't formed and the vicinity of so many hot stars would make any planetary surface quite unfriendly. But that's exactly why these fairly remote clusters are so bright and sparkling. I'm sure that you'll want to see them again and again.

About the drawing itself, the original was made with a simple pencil on white paper, which I subsequently inverted and edited in Photoshop to render it as realistic as possible. You can imagine that given the enormous amount of stars I've spent about 2 hours behind my binoculars in order to draw them all. One of the main difficulties with drawing rich and complex clusters is that eventually your head will start to spin and you wonder whether you've already drawn a certain tiny little star or not. You'll start seeing stars all over the place and think that you're about to go crazy! :-) Another difficulty is that with time, the image in the binoculars will rotate, as the sky moves along with the rotation of the Earth. So the references you use to determine the position of the stars for your drawing will rotate likewise and this creates a lot of confusion. But in the end I'm quite pleased with the result and I hope you like it too.


Tuesday, 5 January 2016

Welcome to the world of Astronomydrawings

Hello all!

Since the dawn of civilisation man has been overthrown by the beauty of the heavens. There is no culture in which the stars were not admired, studied or even endowed with magical, if not divine powers. These days on the other hand there seems to be an evolution towards disinterest. Apart from a minority called “nerds” or “weirdoes” nobody still looks up at the nightly sky anymore. Of course, useless public lights have reduced the incredible spectacle of millions of stars to a mere shadow of what it once was, apart from an ever smaller part of extremely remote or uninhabitable areas.The sky’s usually no longer pitch-black but a dirty kind of orangy-grey and obviously a lot less attractive to look at. But still one could be surprised at how much there really is to see and discover up there. Just take out a cosy camper bed and make yourself comfortable in your garden or terrace, preferably when the sky’s really transparent and when there’s no moon around. And then... just look up and let yourself be swept away by what you see. There’s no better way to put things into perspective and make you feel humble, yes, even insignificantly tiny in the middle of the seemingly infinite vastness of the universe. Or grateful for the universe’s magnificence. And once you’ve really become enchanted, you may even want to take up astronomy too and become a member of the “weirdo-club”, spending entire nights behind your telescope in the freezing cold. 
Well, let’s not take it that far yet and start from the beginning. There's an infinite amount of books, websites and forums about astronomy. You've probably already been bewildered many times by the most stunning photographs of the universe and my sketches could never compete with those because I can only draw what I've seen with my tiny little human eyes. Without even considering my limited artistical skills through which I try to give you an idea of what it really was that I saw. But perhaps that's exactly why my blog, and the blogs and websites of my sketching friends, are so unique. You won't find any images here which are the fruit of many hours of exposure time and digital editing necessary to make those pictures so stunning. My drawings are merely the result of often hours behind the telescope and afterwards a lot of photoshopping to render them as realistic as possible. What you see on my drawings, you will likely also see through the eyepiece of a similar telescope or binoculars. 
It is my intention with this blog not just to show you my work, but also to tell you something about the object I sketched and from time to time I will also reveal some of my little sketching secrets. So I'd like to wish you, dear visitor, a lot of fun browsing through my posts. Hopefully, you’ll find them inspirational.

Peter