Archive for March, 2016

ISS close to Jupiter – March 31, 2016

Posted in ASTRO on March 31, 2016 by maxpho

Recently, an image depicting the transit of the International Space Station over the planet Saturn was posted on different websites and a lot of fame came to the so-called author. It was later proved that the image was a fake, and some prestigious websites removed it altogether from their pages. The author stated that (after a lot of discussions on different forums between amateurs that knew how difficult it is to get such an image) that he was actually depicting a simulation of such an event. Well, I can now prove just how difficult such a transit is to image…

The transit ephemerids were computed using the CalSky website.

Together with my wife and her brother we’ve traveled for around 40 kilometers from home to witness just such an event, a transit of the ISS over the planet Jupiter. From experience, I knew that the great brightness difference between the two objects will give me some problems; Jupiter has a rather low surface brightness compared with the ISS. If some astro-photographer wants to image both objects at the same time, he must either underexpose Jupiter at such a level where Jupiter will be barely visible in the images, or, he must overexpose the ISS, and doing so loosing some of the structural details.

For this transit I chose a half-way method, with just a bit of underexposure for the planet, and a bit overexposure for the ISS.

The following shots were acquired using the 355mm F/5 Newtonian, a 3x Barlow lens, and the ASI174MM camera with a Green filter. All this was placed onto the EQ6 mount. I do believe that in order to get the ISS sharp (with no motion blur due to its high speed) and with a decent level of details, one must use a rather large scope in order to cope with the great brightness difference of the two objects (such as Jupiter and Saturn). The camera setting were: gain at maximum, and exposure time at 0.5 milliseconds (1/2000sec in photographic terms). This allowed me to have a frame rate per second of 90, which was good enough to capture the Station in seven frames.

And before I start with the more or less processed result, I shall post the most-processed image of the event, a 1800-frame stack for the planet and two satellites, with the ISS position from the seven frames placed in a different layer and blended with “lighten” in PS CS2. The image shows some nice details on the planet (like the Great Red Spot) and also the two satellites towards the right (Io is the one closer to the planet, and Ganymede is the other).

The shot also shows just how difficult it is to get the ISS over such a small apparent diameter: despite being on the predicted “totality” band, the ephemeris errors are always large enough that the event is practically impossible to catch. I think that 100 meters away the ISS would have been at least partially transiting the planet.

1800 FRAMES ISS.jpg

And now only the seven frames which captured the ISS, again blended using “lighten” in PS CS2. Note how few details are visible on the planet, and the satellites are almost impossible to spot.

SEVEN FRAMES.jpg

To have a “true” sense of the actual data, here is a raw frame of the event, with no processing (only .bmp to .jpg conversion). The hour of the event is present in the file name.

Single205859.jpg

And now two animations. The acquisition rate was at around 90, while the first animation presents the event at 20fps:

AT 20FPS.gif

And a slower 3fps version:

3FPS.gif

UPDATE:

The first shot from this post was published on the SpaceWeather site.

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Comet 252P/LINEAR – March 31, 2016

Posted in ASTRO on March 31, 2016 by maxpho

There is a new comet visible in the morning sky. It’s name is 252P (LINEAR). For now, the light of the Last Quarter Moon is interfering with the visibility of this object, but in the next few mornings the view will improve significantly as the Moon decreases and the comet gets higher.

I’ve got a chance at imaging this comet after a long imaging session with the planet Jupiter. This green fuzzy was easy to spot on the raw frames, but for now it is impossible to see it with the naked eye, and it may remain that way since the comet is receding from us.

The following shot is a stack of 31 frames, each a 30 second exposure at ISO 400 with the Canon 550D and a Canon 100mm lens mounted on the EQ-6. The Last Quarter Moon was close-by, and hence the strange background (I had to use PS for a lot of background correction).

252p.jpg

The comet is rather easy to find for now, being placed near two planets: Mars and Saturn.

The following mosaic shows just how interesting the morning skies are:

CometPlanets.jpg

Retezat Mountains – August 1/5, 2015

Posted in Concedii, Plimbari, Specii rare on March 30, 2016 by maxpho

The second trip of 2015 inside the Retezat National Park. The following shots span on a period of five days and present some of the butterfly species that may be found in different areas, as well as two individuals of the species Vipera berus. This trip was focused on different activities regarding insect species mostly, not so much on photography. This year (2016) it will be a little different I think…

First, some mountain views:

Hateg.jpg

defr.jpg

pano pietrele bucura.jpg

mountainview.jpg

walk.jpg

peisaj 3.jpg

And the two Vipera berus individuals:

vip 1.jpg

vip 2.jpg

vip 3.jpg

vip 4.jpg

And the second one, perhaps the most beautiful individual of this species ever found by me (and I did find around 20 in the last few years):

IMG_2237.JPG

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And now, for the butterflies…

Aglais urticae:

aglais.jpg

Apatura iris:

apatura 1.jpg

apatura 2.jpg

Apatura ilia:

ilia 1.jpg

ilia 2.jpg

Thecla betulae:

lic.jpg

Nymphalis antiopa:

nymphalis 1.jpg

nymphalis 2.jpg

Papilio machaon:

papilio.jpg

Nymphalis polychloros:

polychloros.jpg

Minois dryas:

satirid 2.jpg

satirid.jpg

Superb few days…with superb many species…

Vipera ursinii moldavica – July 28, 2015

Posted in Specii rare on March 27, 2016 by maxpho

Last year, during a Physics conference at which I’ve participated in Iasi, I had the immense luck to find one of the more endangered viper species in Romania.

The species name, Vipera ursinii moldavica, is representative for the general location where this viper can be found.

The danger to the survival of this species comes mostly from urban expansion, at least for one of its habitats. From the two locations closer to Iasi, I’ve visited only the one at “Valea lui David” (David’s Valley), west of the city:

Valea Lui David.jpg

Two interesting articles guided me in finding one of the locations where the species is (still) to be found (article 1, article 2).

After a no-success trip in July 2013, in 2015 I’ve returned at the same location, this time with a little bit more time on my hands, and a lot more determination to find at least one individual. The rush was due to the rapid destruction of the habitat, visible (for me) in just two years. The construction of more and more buildings at the entrance of the reservation, and the increasing number of plastic bottles on the road that cuts through the valley signal a fast degradation of the habitat of this unique reptile.

Somehow coincidentally, the first of the two individuals found during the few days I’ve visited the area, was observed on July 28, my birthday. It was surely a very nice gift!

The shots of this individual:

vip 3.jpg

vip 2.jpg

vip 4.jpg

vip 1.jpg

The second individual, a more aggressive one, were shot on July 30.

vip b 1.jpg

vip b 2.jpg

vip b 4.jpg

Of course, there were many other species present at this location, especially insects, from which I’ll mention the very large Saga pedo:

saga pedo 2.jpg

saga pedo 1.jpg

saga pedo 3.jpg

And the Mantis (Mantis religiosa), which was by far the most numerous large insect during my visits there:

mantis 3.jpg

mantis 1.jpg

mantis 2.jpg

I truly hope to find in the next years the habitat at “Valea lui David” at least in the same condition as it was in 2015, if not better (free of junk and no other buildings inside the perimeter).

And of course, a lot more individuals from the species Vipera ursinii moldavica in the tall grasses 🙂

The Moon and Jupiter – March 20, 2016

Posted in ASTRO on March 25, 2016 by maxpho

This results are from a session that was almost stopped due to poor seeing conditions. I think I’ve said to myself that night a few times “maybe it will get better in a few more minutes”, but that never happened. Nevertheless I was able to extract something from the many (130 Gb) files acquired. The setup was composed from the 355mm F/5 Newtonian, the ASI 174MM with a Red filter for the Moon shots, and the RGB filters for Jupiter, and some Barlow lenses in between (a TV 2X Powermate and a Baader 2.25x one). Seeing was “stable” for the entire session, at around 5/10, with a staggering maximum of around 7/10 for a few seconds…

And now the shots.

Crater Tycho:

TychoMax.jpg

The crater Stadius with the nearby Copernicus in shadows (lower left) and Eratosthenes:

StadiusMax.jpg

And Clavius on the terminator:

ClaviusMax.jpg

And now for Jupiter, again, in poor seeing conditions, but with a large shadow (from Callisto) visible:

JupiterCallistoMarch17.jpg

And one animation showing Callisto exiting the disc, and Io leaving the field of view at left. The frames were made from the Red channels only:

JupiterCallistoRed.gif

Hope for some better conditions next time I’ll get the big scope aimed at Jupiter…

 

Crater Gassendi and a lot of rilles – March 20, 2016

Posted in ASTRO on March 24, 2016 by maxpho

And another lunar image pair from the March 20 session.

This time it’s Gassendi and the many rilles around it that makes the subject of the following shots. Same equipment as for the previously posted images (355mm F/5 Newtonian with the ASI 174MM camera and a red filter), and again with the F/30 and F/20 comparison. Same seeing conditions (6-7/10).

Gassendi largeMax.jpg

GassendiSmall.jpg

The Aristarchus Plateau -March 20, 2016

Posted in ASTRO on March 22, 2016 by maxpho

I’m continuing with the image processing of the March 20 lunar session. This time the subject is the Aristarchus area, with Vallis Schröteri near the terminator.

The images were both acquired with the 355mm F/5 Newtonian and ASI 174MM camera with a Red filter in 6-7/10 seeing conditions. The first shot was acquired at F/20 (and enlarged to 120% in processing), while the second at F/30 (it was resized to 90%). This comparison shows that it is not wise to go too far with the magnification, if the seeing is not close to perfect…

AristarchusMax.jpg

AristarchusPlateauMax.jpg

I’m also posting two links from the LPOD site, where Chuck Wood made some scientific comments regarding this interesting region: link 1, link 2.