Messier object: M13 (Hercules Globular Cluster)
Star Cluster: IC 4665

Alcor, HD 116798, Mizar

Location: Home
Date: 2022-07-30/31
Time: 10:00 PM - 1:30 AM ADT
Equipment: EVOSTAR 80ED + 25 mm & 9.7 mm eyepieces
Transparency: Very Good (4)
Seeing: Very Good (4)
Temperature: 17º C - 16º C
SQM: 19.72

No cloud, light breeze. Dew had already set in but hand warmers were applied to the scope and finder scope. Mosquitos to start the evening. Jackets not required for much of the evening. This was a session to hopefully overcome the alignment challenges experienced at Kejimkujik the weekend before (don't ask). Success with North level alignment, although it did require some minor slewing to centre the stars before saying 'yes, that's it'. I also had a new dual-circle reticule finder scope with which I practised 2-eye vision (just as Blair suggested years ago that I try).

The goals I set for this evening were to hopefully view some Messier and/or some of the DSOs in the now defunct constellation Taurus Poniatovii ("Poniatowski's Bull") - thanks, Dave, for showing me the Briaan Ventrudo article in Sky & Telescope (A Visit to Taurus Poniatovii). Success on both counts - not overwhelming success, but success nonetheless. I stayed out until 1:30 before taking down and after attempting to find a few other items in Taurus Poniatovii without siuccess.  I would have been out a lot longer had we not been heading to the Valley tomorrow for a day at the beach. 

Mizar (ζ Ursa Majoris) - Alcor (80 UMa) and HD116798
Time: 10:30 PM ADT
Equipment: Telescope + 25.0 mm and 15 mm eyepieces
S&T Chart Reference: 32

After aligning the scope, I attempted to find Mizar and Alcor using the 25 mm eyepiece. It slewed to the correct direction but Mizar was not in the FOV. I had to use the finder scope to get it to the correct place. Found! 

I then switched out the eyepiece for 15 mm and used that view to sketch what was seen. I could actually see Mizar's ζ1 Ursa Majoris and ζ2 Ursa Majoris separated, one slightly larger and consequently seemingly brighter than the other. Interesting that the jury is still out as to whether these are a visual double or whether they are in fact gravitationally bound.

Mizar-Alcor and related star field

IC 4665 (in the asterism Taurus Poniatovii)
Time: 11:18 PM ADT
Equipment: Telescope + 25.0 mm eyepiece
S&T Chart Reference: 54

I had the scope go to Cebalrai (β Ophi) and then slewed to find this open cluster that spells "HI". It literally filled the FOV with so many stars. What I sketched were the brightest of the stars I could see. It wasn't until I had finished the sketched and looked at what was on paper that I realized the stars did in fact spell "hi". Very Cool!

History of Taurus Poniatovii:
In 1777, Marcin Poczobutt, director of the royal observatory at Vilna (Today's Vilnius, in Lithuania), named it after Stanislaw August Poniatowski, King of Plane and Grand Duke of Lithuania from 1764 to 1795. Poczobutt catalogued 16 stars and Jean Fortin included them in 1778 in his Atlas céleste de Flamséed as Taureau Royal de Poniatowski. John Alert Bode added many fainter stars to the asterism in his 1801 Uranographia. It fell into disuse in the later 19th Century. The name remains, though, to describe what currently is an asterism entirely within Ophiuchus.

Sketched Open Cluster IC4665
Labelled IC4665 with Cebalrai (β Ophi)

M13 (Hercules Globular Cluster)
Time: 11:51 PM - 12:07 AM ADT
Equipment: Telescope + 25.0 mm and 15 mm eyepieces
S&T Chart Reference: 52

Using the 2-eyed vision through the finder scope, I had to slew to where I thought M13 was located a little below the line between η Herculis and ζ Herculis. Close. It was in the upper right quadrant of my 25 mm eyepiece FOV.  There was a bright star above it, a semi-circle of stars in the left FOV, and a triangle of stars to its upper right where one star was either a double or just had an optical double.

After sketching the 25 mm view, I inserted my 9.7 eyepiece for a completely different view. I could see the core was quite dense and there was a lighter area around its perimeter. There was a crescent of stars adjacent to it that I could not identify and a bright star in the upper right quadrant (maybe HD 150998).

M3 and its star field, 25 mm eyepiece
M3 and its star field, 9.7 mm eyepiece

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