Hello all,
The culmination of a long struggle to get to this point. New camera and ven though it’s nine months old, the C8’s first light imageWelcome to my Messier 3, NGC 5272 – 2023
Equipment: EQ6-R, C8-A, SV405CC, SV501P 70/400 Guide
Software: APT 4.18, PHD2, DSS, Adobe PS, Astronomy Tools Action Set, Star Spikes Pro.
First Light, SV Bony SV405CC on 3/29/23: 45 subs, 20 dark, 20 flat, 20 dark flat, 20 bias. And even though the tube is nine months old and I’ve managed to get some images out of it, this is the first light, long exposure AP taken with it. Missing equipment was the hold up for the three months. Then actually getting clear skies and working out guiding over the next 5. Long focal length guiding is a whole different can of worms and they love to wiggle. Average RMS for this was about .5. And that was with a polar alignment of 12 seconds total ra error and 45 seconds dec error.
It was discovered on May 3, 1764, and was the first Messier object to be discovered by Charles Messier himself. Messier originally mistook the object for a nebula without stars. This mistake was corrected after the stars were resolved by William Herschel around 1784. Since then, it has become one of the best-studied globular clusters. Identification of the cluster’s unusually large variable star population was begun in 1913 by American astronomer Solon Irving Bailey and new variable members continue to be identified up through 2004.
This cluster is one of the largest and brightest and is made up of around 500,000 stars. It is estimated to be 11.4 billion years old. It is centered at 32,600 light-years (10.0 kpc) away from Earth.
Messier 3 is quite isolated as it is 31.6 kly (9.7 kpc) above the Galactic plane and roughly 38.8 kly (11.9 kpc) from the center of the Milky Way. It contains 274 known variable stars, by far the most found in any globular cluster. These include 133 RR Lyrae variables, of which about a third display the Blazhko effect of long-period modulation. The overall abundance of elements other than hydrogen and helium, what astronomers term the metallicity, is in the range of −1.34 to −1.50 dex. This value gives the logarithm of the abundance relative to the Sun; the actual proportion is 3.2–4.6% of the solar abundance. Messier 3 is the prototype for the Oosterhoff type I cluster, which is considered “metal-rich”. That is, for a globular cluster, Messier 3 has a relatively high abundance of heavier elements.