Monday, 25 September 2017

Cygnus Widefield

It's been a while since my last publication. I sort of grew tired of fighting against the weather in the region where I live... It was always the same. Drive to the location, set everything up, align, find the target, start shooting and then mist or clouds roll in so drive back home... and this happened everytime in the last sessions.

However, this weekend I decided to check if I still remembered how to do this. This time I just did a rough alignment of the mount (NEQ-5) and shot with my Nikon D3100 DSLR without the ETX-70, just with my Sigma 18-50 f2.8 which is way more forgiving with the star trails than the 300mm. This means that this image is not from a specific object but from a wide area of the sky which spans 26.5 x 17.4 degrees.

I aimed high in the sky to avoid light pollution since I was near cities and villages and I was just trying to keep it simple. Around there, close to the cenit, was the summer constellation of Cygnus, right in the path of the Milky Way.  This region is packed with objects and stars although this time astrometry is not tagging my nebulas for some reason but, some of the objects you can see are:  North America nebula (NGC 7000) south to the brightest start Deneb, close to it it is the Pelican nebula (IC 5067). Close to the second brightest star, Sadr, are the Butterfly nebula (IC1318) and the Crescent Nebula, next to the right margin, near Gienah, is the Veil nebula, which I already pictured with the ETX-70 here and here.


The annotated image for reference:

Monday, 22 September 2014

Lagoon - (Sagittarius Special I)

Sagittarius is one of the jewels of the summer sky in the northern hemisphere as it points towards the core of our galaxy. It is a rich region in all kind of deep sky objects and I never get tired or jumping through this area even with my binoculars. One of this awesome objects is the Lagoon nebula.

The Lagoon Nebula (catalogued as Messier 8 or M8, and as NGC 6523) is a giant interstellar cloud classified as an emission nebula. It is one of only two star-forming nebulae faintly visible to the naked eye from mid-northern latitudes. Seen with binoculars, it appears as a distinct oval cloudlike patch with a definite core. A fragile star cluster appears superimposed on it.

The Lagoon Nebula is estimated to be between 4,000-6,000 light years from the Earth. In the sky, it spans 90' by 40', translates to an actual dimension of 110 by 50 light years with an apparent magnitude of 6.0.

On top of the nebula, there is a star cluster known as NGC 6530. This is a young cluster of about 2,000,000 years. 

The picture is composed of 35 lights of 150" each, 35 darks and 40 bias, taken through the 70 mm refractor (ETX-70) mounted on the HEQ-5 (tracking not-guiding) and with the unmodded Nikon D3100 DSLR. The stacking was performed with DeepSky Stacker and processed with StarTools and Photoshop. The new workflow I'm following allows me to constrain the stars and its halo enhacing the main subject in the frame.


And the annotated image as usual:

Monday, 15 September 2014

A "quickie" before the clouds...

That night seemed to be a good one for some astrophoto but, while trying to obtain a good phocus with a bright star, I saw far in the horizon the nightmare of the astronomers. The clouds were starting to form in the coast and the slow winds were coming towards me so it was clear that the night was about to be ruined. With the dissapointed already settled, I decided to give a go to a target close to where I was phocusing and to take the most light possible before the clouds roll in.

M13  (Messier 13 or The Great Globular Cluster) was alredy hunted by me while starting on astrophotography. An easy to locate target in Hercules, bright and amazing as it is composed of 300,000 stars with a brightness of 5.8 and located at around 22000 ly outside our galaxy.

I only had time for 10x120" lights, and some darks and bias with the 70mm refractor (ETX-70) on a HEQ-5 and a unmodded NIKON d3100. Stacked with DSS and processed with StarTools and Photoshop.


The image annotated:

And the old picture close to the new one for comparison:

Monday, 8 September 2014

A long time ago... a galaxy far far away ;) You all know this sentence and this could be one of this galaxies... This time I bring you the whirpool galaxy a.k.a. M51a or NGC 5194 located in the "hunting dogs" constellation (Canes Venatici).

The Whirlpool Galaxy is an interacting grand-design spiral galaxy. A grand design spiral galaxy is a type of spiral galaxy with prominent and well-defined spiral arms, as opposed to multi-arm and flocculent spirals which have subtler structural features. Why this galaxy is a grand-design spiral is pretty clear but it is also an interacting galaxy. Interacting galaxies are those whose gravitational fields result in a disturbance of one another.

In this case M51a is interacting with M51b (NGC 5195) and together comprise one of the most noted interacting galaxy pairs in astronomy.The two galaxies are connected by a dust-rich tidal bridge. The dust in this tidal bridge can be seen silhouetted against the center of NGC 5195. This demonstrates that NGC 5195 appears to lie behind the Whirlpool Galaxy. The encounter has significantly enhanced the spiral structure of M51a and as a consequence of the gravitational interaction with the Whirlpool Galaxy, NGC 5195 is highly distorted.

M51(a and b) are stimated to lie at a distance of 23 ± 4 million light-years from us, well, that's far far away and actually a long time ago, but they're not the only galaxies in this picture. If you look carefully to the image it is possible to depict at least four more galaxies:
- NGC 5229 (on the margin top right partially off frame) located at 17 million ly.
- NGC 5169 second on the left of M51 located at 112 million ly.
- NGC 5173 third on the left from M51, don't mistake it for a star. 111 million ly.
- NGC 5198 left and slightly up from M51, 116 million ly.
- IC 4264 located first on the left from M51  at a distance of 125 million ly.

Now that's far far far far far away. By the time the light left this galaxies, we were in the Aptian age. The continents were still splitting appart in the lower Cretaceous and the dinosaurs were ruling the Earth. Of course no sight of nothing similar to a human/monkey being until a "few" years later and yet here we are, catching the light from that time.

The shot was not really good, too noisy due to light pollution, and the night was not clear though. That's the reason why I didn't try to process it until now. However, recent discoveries in my processing pipeline gave me some ideas to give it a go. It is composed by 30 lights of 120" each, 40 darks and 40 bias with the 70mm refractor (ETX-70) mounted on the HEQ-5 and taken with a Nikon D3100 unmodded. The processing was performed with StarTools and Photoshop.

As usual, ENJOY!

For those of you who gave up looking for the galaxies (bad!), here is the annotated image:

Sunday, 31 August 2014

Eastern Veil Nebula

This image is part of the veil nebula complex in the constellation of Cygnus. A few weeks ago I took a try to the Western Veil (Witch's broom nebula). Today I bring the other main part of the nebula located south of the previous one and enclosing the spherical residual of a supernova that exploded between 5,000 to 8,000 years ago. The Eastern Veil (also known as Caldwell 33)  brightest area is NGC 6992, trailing off farther east into NGC 6995 and IC 1340.

The image is composed by 45x150' lights, 40 darks, 40 bias, 40 flats and 40 dark flats tracking but not guiding with the ETX-70 (refractor 70mm) mounted on the HEQ-5 with an unmoded Nikon d3100. The processing (quite agressive) was performed  with StarTools and Photoshop. I don't fully understand yet the color module of StarTools  so I raised a little the color saturation on PS.

This was a tough one. I would say that the toughest I've doneutil the date. Not for taking the pictures themselves, that being such a faint object on visible light was tricky enough, but for the processing. The images were taking under severe light pollution and the tracking and phocus was not so good. This joined with the ETX-70 and its halo and coma made it quite difficult to process. Anyway, I'm quite happy with the result.


And the annotated image:

Sunday, 24 August 2014

Milky Way - 1st Anniversary

One year has passed since my first approach to the astrophotography and the night sky photographs. It was a picture of the Milky Way, a picture that I always wanted to perform and that seemed so out of reach for me back in that day. I couldn't find a better photo to remember that day that to give another try to that target and check how much my technique and abilities improved during this year.

Taking advantage of a visit to my grandparents house in the rural Galicia, I set the equipment pointing towards Sagitarius and Scorpio, the two constellations that frame the core of our galaxy  and then  I started the shoot. I must say that the Milky Way was shinning over my head as this area has very little light pollution so it was quite easy to frame. 

The cool thing about this photo is that the light dome shown at the bottom of the picture is the city of Santiago (St James) destination of the pilgrims doing the "Camino de Santiago" (Way of St. James). This path, according to the Christians, leads to the shrine of the apostle St. James the Great in the Cathedral of Santiago de Compostela in Galicia in northwestern Spain but, before them, the romans already knew this path towards the "End of the World", Finisterrae. They followed the Milky Way and this area was the westernmost piece of land before the atlantic ocean. Thus the way of St James is also known as "Voie lactée" – the Milky Way in French.

The shot is composed by 8 lights of 150" ISO 800, 4 darks and 4 bias (with more lights the detaild would've been better) with the Nikon D3100 and the kit lens 18-55mm f3,5-5,6 at 18mm f4 tracked with the HEQ-5 and processed with DSS, StarTools and Photoshop.


The annotated image showing the main constellations in this area:

And finally, the evolution of one year:

Monday, 4 August 2014

Leo's Triplet

Some months ago I tried this object but the clouds rolled in and I thought that I didn't take light enough for a good result. After a tough process trying to control the noise here is the modest result.

The Leo's triplet or M66 group is located in the constellation of Leo near the rear paw of the lion. This group is located at aproximately 35 million ly and formed by three galaxies:
  • Messier 66 (also known as NGC 3627) is an intermediate spiral galaxy. M66 is about 95 thousand light-years across. The apparent magnitude is 8.9 being the brightest galaxy in the group.
  • Messier 65 (also known as NGC 3623) is also intermediate spiral galaxy  with an apparent magnitude of 10.25. 
  • NGC 3628, also known as Sarah's Galaxy is an unbarred spiral galaxy. It has an approximately 300,000 light-years long tidal tail. Its most conspicuous feature is the broad and obscuring band of dust located along the outer edge of its spiral arms, effectively transecting the galaxy to our view. The apparent magnitude of NGC 3628 is 14.9 being the toughest one to spot when trying visual on this group.
This shot is composed by 14 lights (3' ISO 1600 no guiding), 20 darks and 30 bias with the Nikon D3100 throught the ETX-70. With more lights the image would've been sharper but the clouds didn't gave me time for that... The process was performed with DSS and StarTools.


And the annotated image: