M12 More than pleasing to the eye.

The globular clusters in the Milky Way are all estimated to be at least 10 billion years old and therefore contain some of the oldest stars in the galaxy. They contain an abundance of low-mass red stars and intermediate-mass yellow stars, but none greater than 0.8 solar masses. There are about 150 known globular clusters in the Milky Way. It is thought that globular clusters formed very early in the vast halo surrounding the nascent galaxy before it flattened to form the spiral disc. Star formation would have stopped in these clusters maybe 13 billion years ago, so only old stars are expected to be found there.

Described by Charles Messier as a nebula without stars, it's discovery almost 251 years ago this May 30th. M12 is fine example of a globular cluster, appearing to me visually in my 110mm as a compact dense core with a fainter outer shell. I have the luxury of shielding myself from extraneous light inside the observatory but I still like to cover my head with a dark towel and allow just the faint photons of light to touch the retinas. Somewhat smaller than M13 my eyes are drawn to the triangular shaped 3 stars to it's lower left resolving them to starlight points easily. I wanted to highlight that with this image taken Tuesday night with what was one of the best clear nights of the year. Just over 20 degrees above the horizon and tainted with the light from the nearby town of Watton. I limited exposures to 10 minutes and this was just about the limit as a gradient was becoming a problem. 2 Hours in total calibrated and stacked in Maxim and processed in Photoshop using several layers in an attempt to keep the core stellar like. My focus was a fraction off as 12th+ magnitude stars show a little blooming, noticable when stretched so I have sacrificed some of the background stars. Having never image M12 before I am pleased with the result.

3 pixels

I know there is still plenty of time to capture the spring galaxies. Well not for the next week at least with the full / waning moon spoiling the Eastern skies. However I started a Galaxy project The objective was another deep field to image as many of the Coma cluster of galaxies. First estimate was approx 1200 -1500. I will be happy with that.

 I  started with the accumulation of 3 hours in 20 minute subs with flats using the William Optics GT81 and starlight express camera. Resolution was 3.37"/pixel with a field of view at 2.83° x 1.88°. I also captured another 5 hours 40 minutes from the FLT110 TMB with darks and flats. Resolution would provide 2.09"/pixel. in a 1.75° x 1.17° field. Unfortunatly I did not manage to keep the angle of camera rotation the same so the final fov would be somewhat smaller. Calibration worked  reasonably well in Maxim, a few hot pixels remaining not 100% happy with the flats from the 81mm either. The 81mm frames scaled to the 110mm's ok though. Processed with just levels and curves in photoshop. Definately a gradient there. I will have a go at that later.

Platesolved in Maxim DL and compared against Carte du ceil. I have several faint galaxy catalogues added and immediately CDC filled with little round circles. I am certainly not going to label all of these???. With probably only a few dozen of our own galaxies stars in the field, everything else is a galaxy mostly from the Coma cluster. This is where the fun begins. CDC labels the PGC galaxies to magnitude 20 anything deeper just leaves a blank. One particular example was labelled PGC 4628378. Listed as 0.0 x 0.0 ' in size and no magnitude it states it's listed under the HyperLeda Database for physics of galaxies. A complex search of 13,000 databases made the task somewhat tougher than I expected as there have only 6 bibliographic references have been made since 1950 on this object. The Hyperleda database splits into many sub categories and redesignated our fuzzy as GMP3397. This was confirmed by the use of Aladin and images gathered by the Sloan Digital Sky Survey SDSS. (pictured). I also cross referenced the data with the Keck/LRIS spectroscopic confirmation of Coma cluster dwarf galaxy membership assignments 2010.

This was starting to gather pace like finding a great great great uncle on Ancestry.com.

Using the VizieR Online Data Catalog: GMP catalogue: galaxies in the Coma cluster (Godwin+ 1983). Classification confirms it is a galaxy within the cluster one of 6724 with a magnitude >21 in a 26.3 degree square area centered on the Coma cluster.

Size appears to be 6 x 4 arc seconds. So resolving at 2.09"/pixel that would equate to around 3 pixels on the camera sensor at magnitude 21.84. Bottom left is a 800x zoom and inverted image of the location, CDC photographic plate is on the right. Finally on the left show 3 pixels that are a few shades lighter than the background. This confirms the deepest I have ever imaged.

The 2nd line confirms RA and Dec and a magnitude of 21.84