The Telescope
ParamountME Robotic Mount
I think that there are no words to describe this state-of-the-art mechanical and electronic jewel. For any kind of information please look at Software Bisque web site about Paramount ME.
After many months of analysis for any kind of mount on the market, my choice was Paramount ME. There is no other mount so technological and update as Paramount ME.
Since the first night I used the mount I understood that it was a real dream for its capability to point the astronomical objects. Since the summer of 2004 I use the Paramount ME every clear night to point toward any region in the sky and its ability and precision to point an object is really amazing.
Every night a switch on the Paramount ME and the computer that manages it: the only thing I do is to synchronize the internal watch of the computer with a radio-controlled watch, than I establish a connection between the mount and TheSky and, after homing, I can point any object all over the sky with a precision of 40-80arcsec. I do no synchronization of the Paramount with stars, just linking the mount with TheSky is enough to point with very sharp precision any astronomical object in the sky, even if due to bad weather condition I switch on the Paramount after many days of not use.
I am sure that with a better T-Point model this precision can be sharper, but at the present it is more than what I really need: my CCD field is 821x821 arcsec so with an error of only 80arcsec, the pointed object is always very near the center of the field.
I spent sometimes to align the mount as close as possible to the celestial north pole. The first time I set up the mount I used a 6-points T-Point model, than I used more and more points. The latest alignment correction, in July 2005, was the result of a 120-points model.
The present model use more than 180 points and the polar alignment error is around 10 arcsec in altitude and azimuth with a sigma around 4 arcsec.
Every full moon night or hazing night I add more points to this model to get an even sharper pointment precision and better polar alignment. To do this I use Automapper: a software that interact with TheSky and CCDSoft to build up a T-Point model sampling all over the sky.
It works quite well even if I have some problem getting astrometric data from the field caught by the CCD camera. I am not able to find the reasons of this difficulty, but in any case it is not so bad: the ratio between mapped and pointed positions is around 30%.
Telescope Pier
The floor of the dome is a wood lattice structure independent from the main walls. In the middle of this structure the pier for the telescope has been placed.
It is a conic section tube, made of building iron, with a base plate of 70-cm diameter and a top plate of 40-cm diameter. The lower and upper diameter of the conic tube is 50-cm and 30-cm respectively.
The pier, which is 3-m high, has been anchored to the main structure of the building by 16 10-mm diameters bolts. Between the pier and the concrete a sheet of anti-vibrations rubber has been placed.
Inside the pier I put a concrete mixture of Leca (expanded clay) and cement.
On the top of the pier, Roberto, a friend of mine very fond of extravagant mechanical solutions, realized a plate to match the Paramount holding holes and the holes of the pier with a system to easy level the telescope mount.
Celestron 14 OTA
This is absolutely one of the most difficult choices: what is the best instrument for an observatory? The main problem is always the same: the price! As you probably know, the collecting area of a telescope is proportional to the square of the diameter and the price in proportional to the cube or more of the diameter!
When I was at Guillermo Haro Observatory in Cananea, Mexico, along with a 2.52-m telescope I used a Meade LX200 16” telescope. The optical quality was quite good (even if the movement of primary mirror was very uncomfortable), the sky conditions were excellent, with a very good seeing and a very deep transparency.
What about the "Pianura Padana"sky?
I made a series of tests and I concluded that the best quality/price ratio in for telescopes around 14” class and the only commercial telescope of this size, in summer 2002, was Celestron 14 (now there is also the Meade 14”).
I know that there are some top quality telescope such as Optical Guidance Systems or RC Optical Systems that produce some state-of-the-art Ritchey-Chretien OTA, but they are much more expensive than C14 and, which is important, do not forget the installation site: a very good mount makes the difference both from the centre of a light polluted city and from the best astronomical place, but a top class optics with a perfect diffraction patterns placed in a region where the seeing is about 4-arcsec is probably not really the best solution.
Now, please allow myself some polemics on the price of the OTA. In Italy there is an exclusive dealer for Celestron and a lot of dealer that have to buy the telescope from the exclusive one. In July 2002 the best Italian price for the OTA was around 8500-9000 €, so it is more than double the price in the US. So I decided to a do-it-by-myself import. I wrote to some US dealers ( Sky and Telescope and Astronomy magazine have a lot of advertisements of these telescope dealers) and asking to Software Bisque, that furnished the Paramount ME, I got a wonderful price ready for shipment.
In less than 10 days the Celestron 14 was at my door with shipping and custom duties paid.
If all the Italian amateur astronomers should buy any kind of telescope, eyepiece, or astronomical accessory directly in the US, probably the Italian dealers will lower the prices!
Apogee ALTA U47 CCD Camera
Since October 2006, the CCD Camera is an Apogee ALTA U47 with a 1024x1024 pixel back-illuminated sensor.
The previous one was an Apogee Ap47p that, after 2 years of strong use, showed a more and more frequent problems with the shutter that randomly did not open completely or open at all. This kind of problem seems to be well known in Apogee even if there is no reference on websites (Apogee or others) and is due to a performance degradation of an electronic component.
In September 2006 I wrote to Apogee to get a quote for repair, but Apogee suggested me an upgrade to the new ALTA U47 using my sensor. I sent my camera to Apogee and after 10days I got the new one.
At first sight, the ALTA is 'another' camera, with a more robust case, 4 back fan, USB connection, and separate power cable (and supplier). After the first tests I realized that this is a state-of-the-art professional camera. The download time is about 2 second in full frame mode, 1 second in 2x2 binning (the most used for my research). As for AP47p (the sensor is just the same) the quantum efficiency is around 80% with 96% peaks.
The U47 is simply wonderful: the sensitivity performances are the same of the AP47p, but with less electronic noise and a faster and faster download time: a 2x2bin is downloaded in less than 2 seconds so that the efficiency of my observation has been boosted up!
When it is applied to C14, it is possible to reach mag. 17.5 in 20s exposure. Unfortunately, due to light pollution and sky conditions (seeing about 2.2 arcsec or greater) the limit magnitude of the sky is about mag. 18.5 in 60s, 19.2 in 120sec., 19.6 in 4min. The faintest magnitude ever reached is 20.4 with a stacking of 25x60sec esposure during a confirmation of a NEO in spring 2012.
In September 2011 the Camera wqas sent back to United States for a problem of ice crystals inside the sensoc chamber. Apogee made the repair absolutely free of charge, but, sigh, I had to pay for shipment ad duty tax.