Comet PANSTARRS at last!

 Comets  Comments Off on Comet PANSTARRS at last!
Mar 132013
 

At last some better weather here in the UK, and I’m pleased to have been able to see and photograph Comet C/2011 L4 PANSTARRS at last.

I did manage to grab a rushed image yesterday in between the clouds, and this is shown at the end of this entry, but this evening I had better luck and caught the Comet with both a 130mm F/7 APO refractor and a 200mm telephoto lens. (Both using a Canon 350D DSLR camera). Details are on each image.

This one is with the telephoto, the lights in the distance are on the Isle of Wight about 5 miles away.

 

On this one, a scale of 30′ (minutes of arc) is marked which is roughly the apparent diameter of the Moon.

 

Here is my first image from 12th March.

 Posted by at 9:52 pm

Galaxy M106 and Companions

 Deep Sky  Comments Off on Galaxy M106 and Companions
Mar 052013
 

M106 is an interesting galaxy! Situated near the handle of ‘the plough’, in the constellation of Canes Venatici, it is roughly 22 million light-years away, and is known as a Seyfert  galaxy which means it has a very active nucleus. In fact, at the centre of M106 is a super-massive black hole. Now, our Milky Way galaxy has one of those too, as do most galaxies  but not as big as the one in M106. It is the material falling into the black hole that causes x-rays and other unusual emission lines to pour forth from this galaxy.

Besides M106, there are many other galaxies visible in this image. The lovely edge-on spiral  near the bright star at upper left is NGC 4217 and is thought to be a companion of M106. I have annotated a few of the brighter ones on the image, but there are many more if you look closely at the bigger sized image which is available here:

Click here for bigger image

As for the details of how this image was obtained. It was taken over some clear spells during 3 nights in late February and early March. A total of 27, 10-minute exposures were collected over this time through a white (luminance) filter, which is why this is a mono image. I will try and collect the R, G and B colours soon.  The telescope was my TS 130mm APO refractor at f/7 and the CCD camera used was my ATIK 383L.

 

 Posted by at 1:51 pm
Mar 042013
 

Phew! I’ve finally finished working on a large lunar mosaic from last month (Feb 19th) when the Moon was 9.5 days old with a phase of just under 69%.

I previously posted another mosaic from the same evening here which was taken with the same 130mm APO telescope and QHY5L-II camera, but at prime focus. This bigger image was taken with a 2x Barlow and, with the extra projection, gives a scale over twice the previous result. In this image, I had to stitch together over 50 images to create a full lunar mosaic. The result is about 35 mega-pixels (5700×6300), and the jpg is about 3.5 Mbytes. Please click on the following link to see the full-sized result. Please make sure to expand the image to its full size when it has finished downloading into your browser. Then you can pan around the moon.

Click here for full-size image

Below is one of the 50 or so images that were stitched together in Photoshop to create the full mosaic.

 Posted by at 1:23 pm
Mar 012013
 

I’m very excited about the Comet PANSTARRS (full name Comet C/2011 L4 PANSTARRS). It is due to be at its best for us in the Northern hemisphere in mid-March 2013, and since it is March 1st today, I thought it was time to get ready for it.

Firstly the name: Pan-STARRS stands for Panoramic Survey Telescope And Rapid Response System” which is a wide-field imaging facility developed at the University of Hawaii’s Institute for Astronomy. Details about the facility, which is not fully completed, are here http://pan-starrs.ifa.hawaii.edu/public/home.html. The comet was discovered on June 6th 2011 and because it is classified as a long-period comet, it takes the ‘C’ prefix (as opposed to ‘P’ used for short-period comets).

Comet PANSTARRS is the first naked-eye comet of 2013, and it is currently putting on a good show for our colleagues in the Southern hemisphere; Yesterday it was reported at magnitude 2.6 with a 2 degree tail, and it is still brightening.

So, the comet is currently heading towards its perihelion, which is the closest to the Sun it will get, and it will reach there on March 10th. The perihelion distance will be about 0.3 AU (1 AU, or Astronomical Unit, is the distance of the Earth from the Sun). Then, after it has rounded the Sun, and gets away from it a bit more, it will start to appear to observers in the Northern hemisphere. I’ve put together a couple of finder maps below.

The first shows where the comet will be at sunset on March 12th. The map is based on the latitude of the South of England, roughly 50 degs N, and sunset will be about 18:00 UT give or take a few minutes depending on where you are. You need to looking West just after sunset, and the Moon will be a very thin crescent, just over 1 day old. You may find you miss it completely before it gets too low, following the Sun. Mars will be below the Moon, possibly even harder to spot. The comet itself will be slightly up and left of the Moon. On this map, the head of the comet is about 12 degrees above the horizon, and will get lower as the minutes tick by. The tail should be stretching away from the direction of the Sun. You should have some binoculars at the ready and it should be a lovely sight in them, depending on how bright PANSTARRS has become! Interestingly, the planet Uranus is very close to the head of PANSTARRS on this day and, at magnitude +6, may be visible in a decent pair of ‘bins’.

Those with a DSLR camera should use a tripod and try taking exposures of several seconds. Set your camera to manual focus, and focus on the Moon, or Mars or any stars you may see in the darkening sky (your autofocus won’t work!). With the camera in fully manual mode, set the aperture as fast as it will go (the smallest number – f/4 for example), and the ISO setting to 800 or 1600. Try exposures of 30 seconds or so. Mess about with the exposure time – the camera should reveal more of the comet than you can see with your eyes.

 

The following map shows the comet on the evening of the 15th March, also at sunset. You can see that, although it has moved a few degrees from the 12th, there are plenty of evenings to try and spot it. Now the Moon is much higher in the sky, and will be showing a phase of about 16%.

 

Good luck! Let’s hope it puts on a good show.

 

 Posted by at 4:12 pm

A Starburst Cigar

 Deep Sky  Comments Off on A Starburst Cigar
Feb 242013
 

I have been using my trusty old C11 that I normally use for the Moon and planets to take some deep sky objects. The C11 gets used more this time of the year because it is ‘Galaxy Season’. This means that the Milky Way is not dominating the sky to us here at this time of the year as it is during the Summer months when it stretches across the sky, and that means that we can more easily see out of our galaxy to other distant galaxies without the plane of the Milky Way getting in the way.

This galaxy is often referred to a the Cigar Galaxy. It is Messier 82 and it is often shown together with M81, Bode’s Galaxy, but the field of view with the C11 and my ATIK 383L CCD will not fit them both in the FOV at the same time. This means we can zoom in on M82 which is only about 11 arc minutes across.

M82 is a bit of a strange galaxy to look at. It is a ‘starburst’ galaxy, seen edge-on and is also the closest starburst galaxy to the Milky Way. As a starburst galaxy M82 has a rate of star formation 10 times greater than our galaxy. Conditions for the starburst activity were believed triggered by a past close encounter with M81 between 300 and 600 million years ago which must caused gas and dust to be compressed into conditions favourable for star formation.

 Posted by at 1:51 pm

Cruise over the Moon

 Moon  Comments Off on Cruise over the Moon
Feb 212013
 

I’ve been testing a new planetary camera: the QHY5L-II.

Two nights ago, I partnered it with my recently acquired 130mm APO to produce this mosaic of the Moon. This mosaic consists of 8 images which have been ‘stitched’ together in Photoshop. Each image was taken at the prime focus of the F/7 Refracting telescope with the camera taking images at 15 fps (frames per second) at 1280 x 960 pixels.

To cruise over the Moon, please click here: http://www.astro-sharp.com/images/moon/Moon-20130219-130APO-F7-QHY5LII-IDS.jpg

Make sure you show the image at its full size, as your browser will make it fit to your screen to start with.

The image below is a very small representation of the full thing!

 

 

 Posted by at 6:21 pm

A Close Encounter of the Rocky Kind!

 Near Earth Asteroids  Comments Off on A Close Encounter of the Rocky Kind!
Feb 162013
 

There was a lot of media coverage of this event, much increased by the incredible Russian Meteorite fall.

The Near-Earth Asteroid NEO 2012 DA14 made a very close pass to the Earth yesterday (15-Feb 2013). Incredibly, this football-pitch-sized rock passed about 28,000 Km from Earth. Think about that! The diameter of our planet is about 12,750 Km and the Earth-Moon distance is, on average, 384,400 Km. So, this rock skimmed by only two-and-a-bit Earth diameters away!

Anyway, I was determined to grab some images of this event, and luckily it was a lovely clear sky that greeted me as I opened the observatory to prepare at sunset. I had prepared by downloading the orbital elements from the IAU Minor PLanet Center here http://www.minorplanetcenter.net/ , but picking it up was still tricky as it was not in the field of my 130mm APO refractor as expected. Undeterred, I scanned each side of the track and luckily spotted the tell-tail streak of the rapidly moving object on my screen.

Here are 2 images with full details on each. I chose these out of the many I took because they have nice galaxies in them too!

 

 Posted by at 10:57 am

First Light Horse-Head

 Deep Sky  Comments Off on First Light Horse-Head
Jan 312013
 

I recently bought a new 130mm f/7 APO Refractor and have already posted one or two images from this new bit of kit. However, one of the reasons I wanted it was because it comes with a nice focal-reducer/field-flattener that brings the f-ratio down to about f/5. This gives a slightly wider field of view and is optically ‘faster’. In fact it is nearly twice as fast because the speed is related to the squares of the f-numbers being considered. So (7×7) / (5×5) = 49/25 = 1.96.

I’ve had the kit since November 2012, but, I was unable to achieve focus with the reducer in place! To cut a long story short, the reducer went back and it was discovered that the lenses had been assembled wrongly!

Anyway, here is my ‘First-light’ image of the Horse-Head Nebula in Orion. It is an H-alpha image (because the Moon was about) and consists of 11 exposures each of 20 minutes.

 

 Posted by at 4:55 pm

Cosmic Tadpoles

 Deep Sky  Comments Off on Cosmic Tadpoles
Jan 022013
 

A Happy New Year to all!

This is my first astro image of 2013, taken on New Years Day evening. It shows a nice emission nebula IC 410 in the constellation of Auriga. Maybe ’emission’ is an appropriate word here, as these two bright streamers in the stellar winds look like two sperm (or sperms – both seem to be correct) trying to enter an ovum!

 

This image is taken through a 130mm F/7 APO refractor, using a 7nm H-alpha filter. Recorded with an ATIK 383L CCD camera, this is the result of stacking 15, 20 minute exposures. Not as sharp as I had hoped – I think the seeing was a bit poor last night, as precise focusing was very difficult!

 Posted by at 1:53 pm

A Heart (but no Soul)

 Deep Sky  Comments Off on A Heart (but no Soul)
Dec 272012
 

As the weather here in the UK is still terrible, I’m still messing about with older data. Here is a re-processed image of IC 1805 – The Heart Nebula which lies in the constellation of Cassiopeia. This image, taken through a 7nm Hydrogen-Alpha narrowband filter, is composed of about 8 hours of exposures, each of 20 minutes. To help appreciate the apparent scale of this image, the full moon would fit about 4 times across it, but the field is not wide enough to include the nearby Soul Nebula – hence the title for this blog entry.

This large emission nebula is a region about 200 light-years across and lies in the Perseus arm of our Milky Way galaxy. Our Solar Syatem is located on the Orion-Cygnus arm which is just ‘inside’ and next to the Perseus arm. The IC 1805 region is about 7,500 light years away (compared to the overall diameter of the Milky Way which is roughly 100,000 light-years across).

 

This emissions from this lovely nebula are powered by a cluster of hot, young stars, collectively known as Melotte 15. ‘Young’ at only 1.5 million years old, really means just that, when you consider our Sun is over 5 billion years old. However, some of these youngsters weigh in at about 50 times the mass of our Sun, and will burn bright and fast. Here is the center of the Heart in more detail.

 Posted by at 1:18 pm