Eclipse of the Moon

Last week has been dominated by eclipse of the Moon. We had a trip for possible locations (with a romantic ruins on the horizont) week ago. Our weather condition was really poor during eclipse time so the phase of totality has been obscured by cloud completely. There are a few pictures and one animation to illustrate the times.

The trip is also documented on pages of Janapka and on Galaxy tea.

A lake under Apollon's temple at winter. Apollon's temple is a part of Lednicko-Valtický areál.

A detail.

A lake below Apollon's temple. Pálava on horizont.

15cm telescope of HaP MK Brno during eclipse. Thx Peťoš.

A link to animation of clouds and halo before eclipse.

First spectra by SGS

Last year, we purchased the SGS spectrograph. I spend today's afternoon by acquainting myself with the device. First images looks really amazing. All ones has been acquired in my office with a scattered radiation of a fluorescent lamp as a light source with our new ST-8 XME camera as a detector. Compare my findings with its spectrum.

An image of a spectrum of fluorescent lamp in low-resolution mode of SGS. The wavelength interval is about 300 - 900 nm. Ultraviolet is on the left, red is on the right.

An image acquired in high-resolution mode. Wavelengths in interval 490 - 650 nm. The orientation is the same as in previous case. The image covers approximatelly central quarter of the low-resolution spectra (try find of Tb - Eu series between two strong lines).

The image of the same lamp acquired by a digital camera (Canon EOS 30D) and a simple CD spectrograph for comparison. You can simply identify global spectral features. The strong red line corresponds to the strong line on the right on high-res image of spectra. The green line is the strong line on the left of the same image. The lighter horiznotal line has been used for construction of a first graph on image below.

A calibrated graphs of spectra of the images above (click for original size). Top to bottom: spectrum by CD's "grating", low-resolution of SGS, high-resolution of SGS. The graphs exhibits different spectral resolution of all "instruments" (look on series of Tb and Eu at 570-600 nm) and different spectral sensitivity (color graphs, line at 550nm).

Once, the spectra looks really fine, I'v worries about simple use of our equipment. The CCD can be connected to spectrograph only without filter wheel (due to focusing range) but the removing of the wheel is really complicated and delicate operation.

Rojetín - preliminary 21 mag/"

Today, I processed zenith's images of night sky taken during Saturday's trip to Rojetín. Original RAWs has been converted to FITSes by rawtran.

Dark frames has been processed by mdark utility from Munipack. My fast statistical analysis of a noise of the dark images shows pretty Gaussian histogram with center on level 380 and thickness about 7-8. The noise looks little bit greater then noise of our CCD camera at the same temperature (approx. 0°C). The dark frame reveals a smooth electro-luminescence at a corner probably due to a fast transfer of electrons to an A/D converter.

The converted light images has been corrected by the darks. The application claimed a small modification of rawtran because our camera detects a gravity direction and it automatically rotates images to a portrait orientation and rawtran needs rotate it back (if not, the size of lights and darks are different).

A combination of our Canon 30D camera and our 17mm Canon's fish-eye gives us a scale about 21 pix/°, eg. 2.9' per pixel near center of projection. I determined the value by use of two stars (therefore it is preliminary only!). A precise analysis will need construction of a model of the projection.

All light images has been processed by muniphot by a standard way (determination of a mean background, finding of stars and an aperture photometry). To my surprise, it works without any troubles. The number of found stars for 3-σ is almost 13 000 and for 1-σ over 50 thousands (!). The limiting magnitude of stars (1-σ) has been determined approximately on 10 magnitudes for 30sec in wide-band of sensitivity of our camera. The photometrical calibration (determination of a zero level for instrumental magnitudes by using of known stars) shows a relative great scatter for stars in the interval 2-7 mag. The position on the chip (near center or border) along with position in Milky way doesn't matter. Opposite with this, the color of stars is important and red stars are unusable for it. It may be due to a mist (or another reason).

My determination of sky brightness on place non-confused by Milky way but near of zenith gives value of 21.0 magnitude per square arcsecond with uncertainlity not better than 0.5. So the place satisfy of hard requirements for our observations.

ISS+Atlantis

Another shot of ISS and Atlantis taken 11. feb. 2008, Canon EOS 30D, 30sec., fish-eye at the observation roof of HaP MK Brno.

Rojetín's night sky

I found the "airport" month ago. Yesterday, I did a first night's trip to the location. The drive troughout darkness and a relative sparse settled landscape is a amazing adventure. Any ambient scenery is pretty unrecognizable. The darkness on the airport is absolute. Only a few far lights is directly visible. The airport is completly abandoned so I didn't meet any car during my about hour stay on the place.

I had only our Canon 30D and our fish-eye (no a tripoid or no a mount). All images has been taken with a static 30sec exposure and with the camera positioned by anything possible (a hinking map, a car atlas). An objective clone has been 3.2 (full aperture), ISO 1600. An atmospheric condition was relative good with a light mist and a nice crescent moon.

I'm publishing a few preview images. All images are converted from RAW format as a color pictures to better illustrate a light pollution. No corection on dark frame has been done. The place is practically the same as it was at last visit.

A view to noth-east direction as a equivalent to day's view. There are lights from Rojetín and Ždárec. Bright stars are part of Big dippper (center), Ursa Minor (top left) and Leo (right).

A view to south-west direction as a equivalent to day's view. The airport facilty is at right, we can recognize connstelation Orion and Canes Major. Light domes near horizont comes from Březí and Borovník. You can identify an airplane at large resolution picture.

Crescent moon.

Light domes at direction to Brno. A head of Leo on the left, Sirius on the right. The large format of the image reveales Preasepe.

The west's view. Cassiopea on top, Deneb near horizont. M31, Lacerta.

Mars and "the gold gate of ecliptic".

Zenit. A lot of object is vissible. The comet Holmes is near Algol.


A church at Ždárec. One of main light polution sources on north direction.

Expedition Moldavite

A moldavite (vltavín in Czech by river Vltava) is a stone which has been created during a meteorite impact. Main centers of deposits of moldavites in Bohemia are near České Budějovice (yes, Budweiser's origin) and in Moravia near Třebíč town. I (and a group of geologist) had a visit on Moravian's location on last Saturday. We has found nothing but the trip has been really nice... Stones are like a dark glass and they are usually found on ploughed fields.

Our first locality has been situated near border of Třebíč.

The second locality has been below Sádek castle near of Kojetice village. There is a vineyard around center of the picture.

The third and last stop has been at a small wood near Dolní Lažany willage.