The EurAstro Mission to Crete 2004

1. Summary

From June 4 to June 13, 2004, a group of 4 observers from the EPO Astro Club Munich went to Crete and met E. Jehin on ESO mission at Skinakas Observatory. Main objectives were: transit of Venus (TOV) on June 8; imaging/spectro of comets; deep-sky objects and minor planets.

2. Climate

The night sky at Skinakas is very dark except above Heraklion to the North. Overall Bortle rating is 2-3. Limiting naked-eye magnitude is at least 6.
There is a lot of wind: 6 Beaufort is common, with strong intermittent gusts. The site is more suitable for deep-sky than for high resolution imaging.
Temperature dropped to 4°C, and humidity once forced the observers to close the domes.
During the day, orographic clouds occasionally form (elevation of Skinakas is 1755m, with Mount Ida nearby).

3. Equipment

There is a 1.3m reflector equipped for imaging/spectro, and a 30cm flat-field camera (*). A third dome is intended to house a planetarium, and there is a guesthouse with dormitory.
EurAstro brought TOV equipment comprising a 200/1600 apochromat (*) and a Celestron 11 both on a MB100 mount (*), a small CCD, a Nikon D100, a camcorder, a webcam, some telephotos etc..

(*) made by Lichtenknecker Optics, Hasselt, Belgium

4. Observations

BEFORE THE TOV, the Munich team, comprising
- Dr. H. Beuchat, EurAstro Executive
- J.-L. Dighaye, EurAstro Central Chairman
- P. Sala, EurAstro Executive
- Dr. G. Tomezzoli, Mission Supervisor & Local Chairman - EurAstro South
together with
- Dr. E. "Manu" Jehin, Local Chairman - EurAstro West
observed and imaged comets 'T7 and 'Q4 with their own equipment. Wideangle views of the Milky Way were taken.

TRANSIT OF VENUS

TOV observations were partly affected by clouds and wind. Yet Manu could send quasi real time webcam images to the ad hoc site of the Groupe Astronomie de Spa (GAS)
I took white light images of the ingress of Venus, then near-infrared images (ca. 770nm) of the egress of Venus, using the apochromat and the D100. Those images were anaylsed shortly after the transit for timing the contact events. Results were sent to the vt-2004 campaign. The camcorder was mounted behind an eyepiece of the C11 for backup and monitoring. Attenuated white light was used for the ingress, and red light (H-alpha) for the egress. Some comments:
* Black drop: not conspicuous, slightly more pronounced towards the long wavelengths (as one would expect for a diffraction-dependent artefact);
* Atmosphere of Venus: arcs clearly recorded during ingress on purposedly over-exposed images;
* Venus surrounded by a bright halo on camcorder images during transit - probably an artefact induced by video image processing since the pixel size of the halo remains the same regardless of the magnification used.

Dr. Manfred Rudolf, Local Chairman - EurAstro East, joined us, and observed the TOV with a coronograph, first from Skinakas, then next to the beach at Ammoudara which was cloud-free.

AFTER THE TOV, the moonrise occurred later and later, thus giving us more time for comets and deep-sky. Manu, literally ubiquitous, refurbished, reconfigured and monitored both the 1.3m and the 30cm while saving the data and sending numerous e-mails to his colleagues and friends. The acquisition of cometary spectra was somewhat hindered by wind, moisture and configuration concerns, but fine UBVRI images of 'Q4 and 'K4 as well as planetary nebulae and galaxies were taken. Further results will be presented in the EurAstro & GAS websites.

H. Beuchat also recorded minor planets with the 30cm to get their lightcurves.

5. Miscellaneous

Manu came with wife Sabine, child Manon and sister Marie who just started her medical career (quite useful since some of us got sick or wounded...) and was in charge of the touristic activities, such as: visit of Knossos, historic center of Heraklion and Rethymnon, monasteries, seaside, etc..
When not observing, we stayed at Anogia, a small countryside town, at the 'Aris' hotel tended by Ms. Marina Dagianta, of extreme kindness.

6. Acknowledgements

- Prof. Y. Papamastorakis, Director of Skinakas Observatory, advised us as to accommodation and observations. His fellow astronomers, assistants and technicians allowed full access to the Skinakas premises;
- A. Brockmann and É. Gillig prepared our telescope transportation boxes and their shipment;
- P. Farizon, EurAstro Executive, coordinated the observations of our EPO teams (A. Decroix, N. Fistas and P. Fourrichon in Munich; O. Nielsen, Local Chairman - EurAstro North at the AAC in The Hague);
- R. Hess and M. Köppl financially contributed to the mission
...and many more helped make EurAstro 2004 a full success.

PHOTO GALLERY

TRANSIT OF VENUS

The EurAstro Team	Atmospheric Arcs
Ingress in H-alpha light	Egress The image is overexposed to make Venus' atmosphere visible; the double image is due to reflections between the CCD and its cover glass.
Ingress	Detail
The Sun and Venus in H-alpha	Egress

SUN

Prominence

On 8.6. morning, a huge prominence was visible.

Sun in whitelight and in H-alpha

(16.6.2004)

COMETS

C2002 T7

300/2.8 lens	C11 Hyperstar
30cm, monochrome

C2001 Q4

300/2.8 lens	C11 Hyperstar
30cm	1.3m

C/2003 K4

30cm

1.3m

ZOOMING IN THE MILKY WAY

Fisheye 10/2.8	Wideangle 17/2.8
Panorama with 50/2	Panorama with 50/2
Panorama with 50/2	M4 with 300/2.8
M6 with 300/2.8	M6 with 30cm (monochrome)
M7 with 30cm (monochrome)	M7 with 300/2.8
M8 and M20 with 300/2.8	M8 with 30cm (false colors: H-alpha, yellow and H-beta)
NGC 6231 with 300/2.8	NGC 6231 with 30cm (monochrome)
Galactic Centre with 30cm (reinforced false colours) note the absence of spectacular features in the visible wavelengths	Galactic Centre with 1.3m - without any prominent features as well