how to improve the visibility of objects in an Alpy600?

[Juan Jose Pueyo]

Hello,
My question is about how to improve the vision of objects in an Alpy600. I am using it with an SC8" or with an RC12", in both cases at f/6.3. For observation and guidance I am using an Atik Titan which, combined with the SC8", allows me to obtain spectra of stellar objects of magnitude up to near +15. In fact I am limited mainly by the vision of the objects. What kind of camera could improve the performance of the Atik Titan (it is a refrigerated MM CCD)? Juan José Pueyo

[Robin Leadbeater]

The ATIK Titan is one of the best cameras for this application (I wish I had one. I use an old ATIK16-ICS but will replace it with an ATIK 314 when it fails) I measure the spectra of targets as faint as mag 19 using a specially modified low resolution ALPY for example
https://britastro.org/observations/obse ... ebf4faaefe
These targets are much to faint to guide directly on so I guide on brighter stars in the same field. (I first take a long exposure and calculate where I need to place the guide star so the target is on the slit)

Cheers
Robin

[Robin Leadbeater]

Here is an example of the ALPY guide camera image when measuring a galaxy (IC708) using a brighter guide star in the same field

ALPY_offset_guiding.png (152.12 KiB) Viewed 8056 times

The spectrum is here
https://britastro.org/observations/obse ... c89b9255ae

Cheers
Robin

[Juan Jose Pueyo]

Thanks Robin,
Yes, some time ago you already told me about the special Alpy 200 answering a question about how to obtain supernova spectra when they fade. Shelyak does not produce it in a standard way although it might be possible to make something similar using 3D printing. What effective resolution does your Alpy 200 have?
Greetings Juan José

[Robin Leadbeater]

Hi Juan José,

An ALPY with a 200 l/mm grism and standard 23um slit gives a resolving power of ~130 which is similar to the resolution of the SED machine used by the Zwicky transient facility for supernova classification.
https://nickkonidaris.com/sed-machine/
Have you added your name to Shelyak's list of people interested in a low resolution ALPY ?
http://www.spectro-aras.com/forum/viewt ... f=8&t=3083
It is very easy to convert an ALPY600 to ALPY200 if Shelyak can supply a 200l/mm grism mounted in the standard holder. There is no need to buy a complete new ALPY.

Cheers
Robin

[Juan Jose Pueyo]

Thanks a lot Robin. I added my name as interested in a future (?) Alpy200.
Cheers.
Juan José