Archive for October, 2015

From friends

Hello readers in the absence of any astronomical activity on my behalf I’m sharing a couple of observations that I have just received from close friends.

 

First up is a cracking lunar sketch from Frank Mc Cabe Chicago, USA

Darwin and Lamarck- labelled

Crater Darwin at Sunrise

 

This was a night of good seeing just one day ahead of full Moon. The sunrise terminator was at Darwin (130 km.) and Lamarck (115 km.) with Lamarck almost completely hidden in shadow.

What made this an interesting view was how clearly Rimae Sirsalis ( 426 km. long) could be traced over most of its length from the large unnamed crater east of Darwin all the way past crater Sirsalis far to the north beyond the sketch region.

Other craters visible in this sketch include: Dark floored crater Cruger (46 km.), deVico (20 km.), Henry Freres (41 km.) and Byrgius (88 km.)

 

Sketching:

For this sketch I used: Black Canson sketching paper, 12” x  14”, white and black Conte’ pastel pencils and blending stumps.

 

Telescope: 10 inch f/ 5.7 Dobsonian and 9 mm eyepiece 161x

Date: 10-26-2015 02:15-04:00 UT

Temperature: 13°C (55°F)

Clear, calm

Seeing: Antoniadi II

Transparency: 4/5

Co longitude: 68.5°

Lunation: 13 days

Illumination: 96.1 %

 

Frank McCabe

 

 

David Davies, a very keen and widely published imager works locally to me close to Cambridge, look at this wonderful image of globular cluster M2 that he has captured

M2_final_RGB

 

Globular cluster Messier 2, NGC 7089 in Aquarius.

 

M2 has a diameter of about 175 light-years, and is 37, 500 light years distant. It contains about 150,000 stars, and is one of the oldest, richest and more compact globular clusters. It lies well beyond the Galactic Center. Visually it is of apparent magnitude 6.5 and about 6 to 8 minutes of arc in diameter, with a bright, compressed central region of about 5 minutes of arc. As with most globular clusters, M2’s central part is pretty compressed: The dense central core of globular cluster M2 is only 0.34 arc minutes or about 20 arc seconds in diameter, corresponding to a diameter of 3.7 light years.

 

This image is approximately 35 x 26 minutes of arc. So the imaged extent of the cluster is around 12 – 14 minutes of arc.

 

There are numbers of faint galaxies of magnitude 17 – 18 visible towards the bottom-centre (south) of the image.

 

It is a simple RGB image based on data captured on 2 and 8 October under somewhat difficult, hazy conditions aggravated by the relatively low altitude of M2. The image comprises 40 minutes, each of RGB data in 5-minute subs.

 

Telescope: 254mm Newtonian at F/4 with a Tele Vue Paracorr;

Camera: QSI 583 with a Lodestar as off-axis guider

Mount: Skywatcher NEQ6

Location: Cambridge, UK

Software: EQMOD, Nebulosity, Scopefocus, PHD2, Deep Sky Stacker; Pixinsight, Photoshop

A higher resolution image is available at:

https://www.dropbox.com/s/wlmmhq77k5ynt2e/M2.tif?dl=0

Best regards, David Davies

 

On the Moon woo hoo

At last I’m out in the obsy, it is clearish. I have aligned the scopes and I have the magnificent Lunar surface vivid on the monitor screens. The 6″ camera is running through a x3 barlow so the the magnification is high and too unstable through poor seeing! The 20″ and Watec video camera however wasn’t running any increase so the image was stable. The cloud was passing through the field of view blotting out the moon on a regular basis. So when I was drawn to, and settled on marvelous Clavius to sketch, I hit the freeze frame button, so now the sky can do what it likes I have a subject 🙂

Clavius stretches a massive 230.77 Km across with a depth of 4.9Km a floor that is pockmarked with smaller craters. I sketched on smooth black paper, using a variety of water colour and Dewent artists pencils, not my normal pastels for lunar work, I’m very rusty but her is my work timed at 19.30 BST…

Marvelous Clavius

15-10-21-19.00-bst-150mm OG-Clavius-Dale Holt

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