March

[Nightspore]

Mad & Mixed

 

March has been a bit of a mixed bag. With a corresponding mixed bag of telescopes. In the first week I had a couple of good rich field sessions with the regularly used 72ED. On the 6th I got a nice view of the Petavius Rille on the setting Moon. Uranus was also conveniently easy to locate as it was in the lunar vicinity. The next night I could still clearly see the Petavius Rille during a dedicated Moon session with the 72mm Evostar. The fourteen kilometre Messier crater was confidently perceived. Its next door neighbour, Messier A, complete with ejector rays, were clearly apparent in the Sea of Fecundity. 

 

 

I had to wait a further seven nights before the weather would be clear enough to have another dedicated lunar session with my 102mm SkyMax. With the phase now at 87.7% I could just about see detail in the walls of Aristarchus, purportedly the brightest crater on the Moon. Schroter’s Valley, which was basically touching and partially obscured by the terminator, was essentially indistinct. However, I achieved some very fine views in the Sea of Rains. The Montes Recti, Montes Teneriffe, Mons Pico and the Montes Spitzbergen were very well defined and clear up to nearly 200x. The detail in the walls of the impact crater Aristillus and its central mountains were quite spectacularly revealed. 

 

 

On Sunday 20th the 90mm Orion StarMax was in action. 

 

 

I managed to catch the Venus dichotomy at around 05:30 GMT. 

 

 

I used a polarising filter but I could see no real detail. I couldn't see Mars or Saturn.

 

 

At 21:30 the same day I also managed to split one of my favourite doubles for the first time in months. Although by now I was back to using the 72ED again. Izar or ε Bootis is often considered to be one of the finest double stars in the night sky. Struve called the pair ‘Pulcherrima’ (the most beautiful). The Orange Giant primary is only separated from the smaller White Class A2 star by three arc seconds. I tend to perceive the smaller star as having a greenish-white hue with the 72ED. However this isn’t always the case with other scopes. 

 

 

Speaking of other scopes, my Sky-Watcher ST102 StarTravel and 80ED DS Pro Evostar saw action for the first time in a year. 

 

 

On the 22nd it was ostensibly a cloudless sky. Excitedly and enthusiastically I set up the StarTravel on the Porta II/TL-130. Unfortunately it transpired that the overall transparency was poor. Conversely the atmospheric seeing seemed to be relatively good. Apparently strong winds from the south had encouraged copious amounts of Saharan sand into the upper atmosphere. I spent three hours with a 19mm Luminos trying to peer at open clusters through the murky airborne desert suspension. 

 

 

Admittedly not the best eyepiece choice for an f/4.9 short tube achromat. However, I do like the overall ergonomics of the 19mm. If you can tolerate their excessive weight, a bit of edge astigmatism and brightening, the Luminos are fine. By Wednesday the transparency had deteriorated further. I reluctantly discarded the idea of rich field viewing in a Moonless sky and decided to split doubles with a zoom. As a direct consequence of the transparency issues the next three sessions were with my 80ED Evostar. At f/7.5 and with Schott/FPL-53 glass it is eminently more suitable for high magnification observing. I decided to concentrate primarily on double stars. By the 26th and the 27th the conditions had actually improved slightly. This allowed me to see Berenice’s Hair with the 80ED and a 27mm Tele Vue Panoptic for just over 22x at around three arc degrees field. Highlights from the three Evostar sessions included Iota Cass, Algieba, Cor Caroli, M3, Izar, Mu Bootis (Alkalurops), Castor, Phi Cancri and Zeta 1 Cancri. The final session was on a bitterly cold Thursday the 31st with the 72mm ED doublet. The transparency had improved significantly and I got a decent two hours. This makes a dozen sessions in total and equals the amount I achieved in March last year. 

 

 

Astronomical images by courtesy of Stellarium and SkySafari Pro.

[Nightspore]

It's taken me a while but I think I've finally settled on the eyepieces for use with the 80ED.

 

 

The 2" Everbrite was originally intended for the Altair 60 EDF but its visual back doesn't play well with the diagonal nose undercut. The TV is actually lighter than the Baader I was using with the 80ED. The Tak' 1.25" diagonal is for magnifications less than a 1mm exit pupil. Its light weight helps with any vibration/return issues. 

 

 

The unusual and lightweight 'before the diagonal' 2x Takahashi Barlow works well in the Everbrite when used conventionally. It magnifies at 1.6x like this. The 15mm DeLite gives 40x and a 2mm exit pupil. 80x and 1mm with the TV 2x Barlow. The Tak' Barlow gives it 64x nicely straddling the other two magnifications. The three Tak' LE eyepieces were all originally bought specifically for the 80ED. They are an old design but are probably among the finest planetary eyepieces I have ever used. So with these five eyepieces and two Barlows I have a range from 22x to 240x. I'm happy with this selection ... for now ... lol.