A rose in the sky

This is the Rosette Nebula in the Monoceros constellation.
A high resolution photo is available at: http://dark.astrodigital.net

A man is running next to the Orion nebula

This is one of the best known celestial objects. Messier 42 is a combination of a bright emission and a reflection nebula. Do you see the running man next to it?
See also: http://dark.astrodigital.net

Look, there is a horse head in the sky!

The B33 and IC434 nebulas in Orion are among the most prominent regions of the northern winter sky. See also: http://dark.astrodigital.net/p465714843/ef0d2994

The Whirlpool galaxy

This is crop of the following photo. It has been shot at 750mm (f/5.5) FL and a color camera having 7.8x7.8mu pixels.

This is the wide view 1,8° x 1,2°.

A hires photo is available under: http://dark.astrodigital.net
Find more info at http://messier.seds.org or http://en.wikipedia.org

The Jupiter Zoo

What an amazing year! 2011 was a very productive one, offering our astronomy community numerous chances to capture the planets and especially the biggest one; Jupiter! Often, the atmospheric conditions were good enough to make high resolution planetary photography possible even from the backyard!

This is a short video clip of Jupiter on Sept. 26th, 2011 at 20:54 GMT, one month before its opposition. All photos have been taken at 3860mm focal length using a TIS DBK21 color camera on an old Dall Kirkham cassegrain telescope.

This RGB composite has been developed with the software Giotto by following certain processing steps described here. You can easily detect Jupiter's Great Red Spot, a storm having almost the same diameter as Earth. [Wikipedia]

Although Jupiter would need to be about 75 times as massive to fuse hydrogen and become a star, the smallest red dwarf is only about 30 percent larger in radius than Jupiter. [Wikipedia]

The shadow of Jupiter's icy moon Europa can be detected  as a dark spot on some of the images, an evidence of a Sun eclipse on Jupiter. However, this is something occuring frequently.

NGC 2232 in Monoceros

Here we are again! I wish you a happy new earth year 2012. Let's look at the stars again! Towards the galactic disk, in the Monoceros constellation, an impressive open star cluster called NGC2232 is visible even in small instruments. This group of stars has a brightness of 4.2 mag and an apparent size of 53 arcmin in our sky. It has a diameter of approx. 18 light years and its light travels 1200 years to reach our planet [Wikipedia]. A high resolution image is available at: http://dark.astrodigital.net.

How to capture a dancing planet

When Jupiter dances, you may need GRGB !
Since two years I capture the planets by using a powerful one shot color webcam, the TIS DBK21USB. It produces regular avi video files. After stacking the avi files with the software Registax, I produce FITS files, need sharpening. The sharpening step is done by using the wavelets function in Registax. Finally, I split the best FITS image in its three separate channels R,G, and B in order to use one of them as luminance, since my seeing conditions from my roof observatory are usually bad.

I need a luminance! But which one?
Depending on what kind of details you want to visualize on a specific planet (i.e. cloud or surface details), a suitable channel should be used as luminance. See below:

Jupiter and Saturn
I extract the G (green) channel in order to set it as a luminance.  It has a higher resolution than red or blue because of the RGGB mask placed on the camera sensor. Two of the four pixels in the RGGB matrix are green.

Examples on other planets:

Mars
I extract the R (red) channel in order to set it as luminance to bring out more albedo details under my poor seeing conditions.  The red channel does not suffer from seeing so much as the green and blue channel. It has a low resolution, since only one of the four pixels in the RGGB matrix is red.
If you want to visualize the orographic cloud structures on Mars you will want to use the B (blue) channel as luminance. You need very good seeing to get a sharp blue channel. These are very rare especially from roof observatories, where the local seeing also plays a role. Perhaps once a year? I think so.

Venus
I extract the B (blue) channel in order to set it as luminance as the cloud structures on Venus are visible in the blue/UV channel. As I said before, the blue channel suffers more from the seeing than the red or the green channel. Its resolution is also low.

NOTE: If your seeing conditions are excellent, the most accurate method for planet photography is simply RGB. You prevent sacrifying details both in the cloud structures and on the surface of the planets using the classic RGB method. See my latest results on Jupiter at http://dark.astrodigital.net.

If you are interested on how to process a RGB planet photos with the software GIOTTO and MaximDL please visit my homepage at: http://www.astrodigital.net

Photo shooting with IC Capture.AS

This is the software package I use with my DBK21 webcam. One of the advantages it provides is the live display of the RGB values. I pay special attention during the image acquisition, not to exceed the max. values of 255 in each RGB diagram. The screenshot above shows the settings, I always use. When the values tends to exceed the limits (255) during the session, I reduce immediately both the gain and the exposure time.

Jupiter rocks :-)
Jupiter rotates fast! Its rotation is easily noticeable at 3850mm focal length I use. I keep the time window for each avi video file short enough to prevent smearing due to its fast rotation. I developed an application to calculate the allowed time window to capture a given planet, taking into account your telescope/camera system! You can download it here for free. See also a screenshot of it:

Figure: My telescope, eyepiece and CCD calculator

/Panagiotis

I wonder (a poem)

I wonder

I wonder how come the angels fly high

while we are forced to walk

I wonder how come the stars always shine

but we see them only by night

I wonder how come six senses we've got

but we use only the eye

I wonder how come people don't ask

what's beyond the deep blue sky

---

(c) Copyright 2003 by Maria Kafritsas, all rights reserved.

Email: Maria.Kafritsas(@)gmail.com

Please replace the (@) with a @ to contact the author.

Weltenrausch - ein Gedicht (a poem)

Ich springe zwischen den Welten

Lange bleibe ich selten

Ich singe und tanze und taumle vor Glück

Über solche Vielfalt einfach entzückt.


Jeder Mensch ein neuer Planet

Wie er lebt, liebt, wie er geht

Was er glaubt, sagt, weiß über sich
Was ich lerne mit ihm über mich.


Zurück bei mir zuhause

Froh über die Pause

Atme durch von früh bis spät

Denke zurück so viel es geht.


Kein Spiegel mehr, kein du, kein da

Alles ist anders als es mal war

Mein Stern ist einsam ohne dich

Erinnerungen halten mich.


Die Zeit verfliegt in der Ferne

Ich lebe dort aber gerne

Ein Gast bei mir, spaziert umher

Als er ankommt glaubt er sich leer.


Nun singt er und tanzt er und taumelt vor Glück

Über solche Vielfalt einfach entzückt

Ich bin erfüllt

Geh nicht.

Copyright 2011 by Maria Kafritsas, all rights reserved.

Email: Maria.Kafritsas(@)gmail.com

Please replace the (@) with a @ to contact the author.

A Canon 7D under the stars

Please, sit down and keep cool. We are talking about a hot stuff tonight.

The system consists of a Canon 7D and a telephoto lense on a Losmandy G11 mount with the Gemini GoTo system. The system is guided with a Starlight Lodestar on a small Astro-Professional ED triplet refractor. This camera is a hell of quality. Magnesium alloy, hermetically sealed against dust and moisture, the large display, a professional long life shutter (150'000 cycles!), agile knobs everywhere and a beautiful body containing 18 million pixels. If you are an astrophotographer, you will never need more pixels in a APS-C format chip. We normally use the 7D at ISO800 for 7 min. integrations during the german summer. A handful shots are usually enough to capture faint nebulas of the Milky Way. We stack them with a freeware called DeepSkyStacker. Note, the software Aperture or Photoshop are excellent to process Canon's raw CR2 files. Oh yes, we are always working with 7D's 14 bit CR2 files to keep the dynamics high. When further processing with other software packages unable to read CR2 files is required, we use 16 bit TIFF files.

Did you know? A Canon 7D is upgradable to Da (a=astrophotography) in several shops here in Germany. Additionally, an IDAS LPS v2 filter can be attached on it, to block out the light pollution.

The clip version of his filter can be attached internally in the 7D. However, there is a normal 2" version  to attach it in the 48mm thread of your Canon<->WideT adapter! 

That's a hot deal, since the 7D with its small 4.3mu pixels is an ideal match for short focal length refractors and telephoto lenses. Since, the achieved resolution isn't trivial, we use a separate small telescope to guide the system. The guiding camera can be controlled by the software MaximDL or CCDSoft, the de facto standards in astrophotography.

A handmade "Hartmann Mask" (the mask having three holes in the photo above) is used for focusing. The micrometer screw at the left side of the telephoto lens facilitates precise focussing. Note, the 7D is remotely controlled from the laptop by using the supplied USB cable. The excellent "Canon 200mm f/2.8L USM II" telephoto lens is used at f/3.5 to take breathtaking wide field photos of large celestial objects (e.g. dark nebulas). This is the best 200mm camera lense for astrophotography, we have ever used so far, no donuts at the corners, no vignetting. Yes, why not, this dream lense could be also used on a full frame camera (e.g. Canon 5D MkII). If you carefully look at the photos, you may find numerous parts being special customtailored products manufactured only on request.

This is the region around the star Tarazed in Aquila. Note, this is a crop of a 9 stacked (median) photos at ISO800 with 7 minutes each. No darks have been used.

Discover more details of this setup at dark.astrodigital.net