Archive for January, 2015

Comet Lovejoy – January 17, 2015

Posted in ASTRO on January 25, 2015 by maxpho

I’ve finally finished processing all of the images from the January 16-18 weekend of comet Lovejoy, from the Cota 1000 site.

The following images are the results from the second night (Jan 17-18), acquired with the TS 65Q APO Refractor (65 mm diameter, 420 mm focal length) and Canon 550D with guiding via PHD software onto the NEQ6 mount.

The base result is a stack of 15 frames at ISO 800 and 1600, and exposures of 4 minutes.

q2 Lovejoy 17 ian 65q b

While trying to get the best out of the images, I’ve ended up with a few versions of the original image, some which present perhaps better the tail details. The sequence below shows the following:

-the final version of the image in colors, with stars;

-the same image but a little over-exposed, in black-and-white;

-the same as the previous, but inverted to better see the tail;

-a specially processed image to get the best out of the tail details, with no stars;

-the same as the previous, but inverted, again to better see the details in the tail.

q2 Lovejoy 17 ian 65q

And a small mosaic, out of 5 frames at ISO 800 and 5 minutes exposure for each panel, showing the extent of the tail:

mozaic 65q

The comet is very dynamic still, but since the weather these days is not cooperating, I can only watch the evolution of the comet’s tail on the Internet…

Hope I’ll get another personal view of Lovejoy soon.

Max

Comet Lovejoy on the night of January 16, 2015

Posted in ASTRO on January 20, 2015 by maxpho

Despite the fact that the following images have been acquired on the same date as the ones in the previous post, I will present them in a new one, since the acquisition and processing were done in a totally different manner.

The frames were acquired with an 8″ F/5 Newtonian telescope equipped with a Baader MPCC (coma corrector), and the trusty Canon 550D at ISO 800 and 1600. The setup was mounted onto an EQ6 equatorial mount, and guiding was done via a 50 mm F/4 finder scope with Meade DSI I camera and PHD software.

I will start with a wider image showing some of the inner part of the comet’s tail. The image is a two-panel mosaic, each a 3×5 minute exposures at ISO800.

q2 two frame mosaicThe same image now, in three differently processed ways, to better discern the tail:

Q2 Jan16 8inchAnd a four-panel mosaic, each panel made from a single frame shot at ISO800 for 5 minutes.

large mosaicThe next images show an even smaller part of the tail, but this time the acquisition was a bit different: 13 frames, each a 1 minute exposure at ISO1600, were stacked using the nucleus as the alignment point.

Comet Q2 Lovejoy Jan 16The image shows the delicate filament-like jets of dust and gas. The jellyfish aspect of the comet is even better seen in the following sequence, presenting one more processing mode (with less stars), and the corresponding negative version.

3versionsTo see the main differences between the two processing techniques, a direct comparison (at the same scale) is shown below:

Comparison for alignmentIt can be easily observed that despite the brighter appearance of the image at left, and the pinpoint stars (and also some galaxies), the finer details in the comet’s tail are washed out due to the longer exposure time (5 minutes for each of the three frames) which meant that the comet moved a lot among the stars. This is not true for the second image, where the 1 minute exposures captured only a small movement of the comet, so the finer details remained better resolved.

And now, another image, a combination of the two from above, but still with a lot less details compared to the one on the right in the above comparison:

new q2

Some small galaxies cam be discern near the comet’s coma.

Still, a truly correct image showing the smallest details could be acquired with only very few short-time exposures, but this also requires a large diameter short-focal scope, and of course…perfect skies.

A small animation shows just how fast the comet was moving in just 14 minutes. Look for the tail changes as the gas and dust particles move away from the nucleus:

q2 jan 16Too bad the skies did not cooperate this time…It would have resulted in a nicer and perhaps longer tail-panorama, and also a longer and better animation.

Max

Comet Lovejoy near the Pleiades – 16th and 17th of January, 2015

Posted in ASTRO on January 19, 2015 by maxpho

For this last weekend I had a great plan: two trips to Cota 1000 (Sinaia) for catching comet Lovejoy near the Pleiades star cluster.

The equipment that myself and my wife had with us was quite enough for catching either the comet and M45 (the Pleiades) or the very-long tail of the comet. Despite our best hopes, the transparency at an elevation of 1000 meters was quite poor (3-4/5) with the Milky Way visible only around 2/3 of the entire length above the horizon, and the comet’s coma almost at the limit of naked-eye visibility.

For now, only some of the images are processed, with the ones with better tail detail still in the processing stage.

The more artistic shots are a two-man’s job, with my wife acquiring the images and myself processing them.

Her equipment: Canon 550D at ISO1600 and Canon 100mm Lens at F/3.5. Only 15x180s frames were stacked, out of 23-24 for each night.

The first one, from the night of Jan 16-17:

Comet Lovejoy and the PleiadesAnd the one from the night of Jan 17-18:

Comet Lovejoy and M45And since the atmospheric conditions and equipment were basically the same over the two nights, I’ve “glued” together both of the above images into a single one frame, showing both the change of the comet’s nucleus position and that of the comet’s tail shape:

Comet Q2 16 and 17Unfortunately we had to go back home the third day. Otherwise we could have got a third position of the comet, much closer to the Pleiades.

On the road back we had the pleasure to see a very bright sundog:

parhelie 2 parhelie 1I will continue the work on the other comet images, and soon they will be posted here.

Max

Comet Lovejoy on January 12, 2015

Posted in ASTRO on January 15, 2015 by maxpho

Another imaging session with Lovejoy, this time from January 12, again from the Comana Woods.

The imaging setup was the TS 65Q APO Refractor and the Canon 550D at ISO 800 and 4 minutes for each of the 14 exposures. The sky conditions were not great, with a lot of humidity in the atmosphere, and light pollution.

The main result from that night shows the impressive inner tail structure:

q2 color bA grayscale version:

q2 bw bThe length of the tail is also very impressive. The following image is a two-frame mosaic, each a 5 minute exposure at ISO 800.

MOZAIC b

I was able to catch some tail in a single frame also, framed by the near-by stars:

single a

It is rather hard to catch both the background stars and tail detail in the same image, as the comet moves very fast. This is well visible in this 14x4minutes animation:

q2 Jan 12

I’m still waiting for a true dark sky up in the mountains to better catch the superb tail of the comet.

Max

Comet Lovejoy and the Pleiades – January 13, 2015

Posted in ASTRO on January 14, 2015 by maxpho

Another imaging run with Lovejoy under the darker skies of the Comana Woods. Darker compared to my closer-to-home observing location, but far from the true dark skies up in the mountains.

This time, besides the “normal” image acquired with the TS APO 65Q, I’ve also shot a wide-field image showing both the comet and the open cluster M45 in the same field.

The tail of the comet is quite long now.

q2 si m45The image above is a 9-frame stack, each a 4 minute exposure at ISO800 with the Canon 550D and a Sigma 50mm Macro lens at F/4, all on the EQ6 mount.

And the “normal” shot using the TS 65Q APO Refractor (D=65mm, F=420mm) and the Canon 550D at ISO800 and 1600, with PHD-assisted guiding, 15 frames with exposures from 240 to 300 seconds. The tail of the comet seems to get brighter.

COMETA q2 13 ian

I have another planned session for tonight, so perhaps better images are going to be posted here.

Max

Comet Q2/Lovejoy inner coma details – January 11, 2015

Posted in ASTRO on January 12, 2015 by maxpho

While testing my old 8″ F/5 Newtonian’s new look (meaning a lot of modifications) together with my wife, I got a brief chance at observing and imaging comet C/2014 Q2 (Lovejoy) just before the clouds rolled in.

This time, since I was not very far from home (just 5km South), and that usually means a lot of light pollution, I could only image the inner tail of the comet and the general aspect of the coma, so no long-time exposures.

But, since I’ve wanted to get the best out of the images, I’ve processed and re-processed the image for a few hours (around 3) and got a view showing the some of the inner jets present in the coma.

The equipment used for this session: Homemade 200mm F/5 Newtonian with SkyWatcher optics, Baader MPCC, Canon 550D at ISO 1600, 27 frames each a 30 seconds shot. The time of acquisition was 16:30-17:10 U.T., with only some frames selected from the initial 45.

The first image shows a processed image with only slightly processed inner-coma details. The details inside the coma are the result of applying the Larson-Sekanina filter with a value of 30 degrees.

q2 colorThe second result, a bit over-processed, shows the inner details a bit better, but at the risk of a not so natural image:

q2 colo brA grayscale version of the above:

q2 bwAnd a comparison image showing the final processed image together with the Larson-Sekanina filtered image. The L-S image was processed by removing the stars and increasing the contrast. The L-S inset is at the same scale as the final image, so a direct comparison of the actual filaments present in the inner coma is possible.

Comet Q2 with jetsAnd, a short animation showing the rapid movement of the comet (and the inner part of the tail) moving among the stars:

Q2 Jan 11Very soon I will be again under the darker Comana Skies, so hopefully better images will be posted on this blog.

Max

Venus and Mercury in conjunction at sunset – January 10, 2015

Posted in ASTRO on January 10, 2015 by maxpho

Just I was giving up with shooting the close encounter between the inner planets due to the dense front of clouds, a large clearing at the western horizon made me hope for a possible chance of still seeing the event.

Driving just a few kilometers south from my home, into a large field, I got the chance I was hoping for: the two planets shinned just above the horizon, in between the clouds.

The following images were acquired with the TS 65Q APO refractor (65mm, F/6.5) and Canon 550D at ISO400, with exposure times ranging from 2 to 10 seconds.

Venus Mercury 1

Venus Mercury 2

Venus Mercury 3

Venus Mercury 4

Lovely conjunction…

Max