Experiment with small telescopes

[Christian Buil]

Spectroscopy with small telescope is also possible
(osez la spectrographie avec des petits télescopes !), see:

http://www.astrosurf.com/buil/small_tel ... pectro.htm



Christian Buil

[Christian Buil]

More info about efficiency comparison of small and large on (very) faint target
(FSQ-85 vs C11)

Here SN2012A at V 13.9 :



Also 3C273 (V = 12.5) :



The small telescope page is updated:

http://www.astrosurf.com/buil/small_tel ... pectro.htm

Christian B

[Olivier Thizy]

Hello,


Very similar configuration when traveling: Televue 85mm on a NEQ6 Pro mount with LISA spectrograph. Here is a detailed description of the equipment & software:

* Windows 7 (64bits) computer with ASCOM 6.1 platform and AudeLA 2012.3.12 (two instances run: A1 and A2)

* Mount: NEQ6 Pro with EQ Direct cable controled through EQMOD.Telescope:
-Joystick to move the telescope manually
-Carte du Ciel 3.4.1 for GoTo & star Synchronization (pointing model)
-AudeLA "Autoguiding" module for autoguiding [instance A1]

* electronic Finder:
-75mm F/2 C-mount lens on a Watec 120N+ video camera in parallel to the Televue 85 (alignment made with the mounting ring on a fixed lamp).
-USB2 grabber to digitize the video image on the computer
-AudeLA "Telescope" module to display the image with a cross hair [instance A1]

* Televue85 Optical Tube Assembly with LISA spectrograph:
-Atik Titan guiding camera controled through Atik drivers, ASCOM drivers and then AudeLA "Autoguiding" module [instance A1]
-Atik 314L+ spectra acquisition camera controled through Atik drivers, ASCOM drivers and then AudeLA "Acquisition" module [instance A2]

NEQ6 Pro + TV85 + LISA + Atik

IMG_4277 TV85-LISA-Atik.JPG (205.16 KiB) Viewed 11504 times

I tried a single instance but it was unstable (AudeLA crash) so I switched to two instances of the same software and it seemed to work very well.

General process was:
-switch ON and connect all equipment; set CCD temperature to desired set point (-10°C for exemple)
-"Acquisition" of CCD bias, dark frames (10min) and flat (lot of them) calibration frames with telescope cover on
-GoTo target (Carte du Ciel)
-Center with "Telescope"
-Center on the slit
-Synchronize target on the pointing model (Carte du Ciel)
-Set "Autoguiding" with Tracking ON
-"Acquisition" of a 'one image' short exposure, define an exposure time and number of exposure for spectra
-Run "Acquisition" 'serie'
-Switch "Autoguiding" OFF at the end
-"Acquisition" of neon calibration frames


The good news is that it working very well with AudeLA 2012.03.12 version and ASCOM platform. It is very easy to Go To a target with Carte du Ciel et center the target with the electronic finder. Then standard acquisition with autoguiding during exposure.

I started this setup at OHP local astronomy (CALA) camp...

First night was a test night and I had lot of issues initially with a single AudeLA instance. I also decided to install the electronic finder which helped a lot!

CCD dark frames took long time to acquire. I decided to use 10min maximum exposure time but maybe I should go longer (20min?).


First night targets were: Arcturus, sigma Her (B9V reference star), M57 and beta Lyrae.

Second night with more stars (classification), M1, NGC3628 (to be processed), NGC2392...

Here is the spectrum of M1:

Spectrum of Messier 1

In summary: excellent 'light' configuration when traveling with some limitation on the magnitude reached out...


More image from the CALA camp at OHP and other's spectra at:
http://photos.cala.asso.fr/thumbnails.php?album=45


Cordialement,
Olivier

[Christian Buil]

Très original l'aide apporté à la crémaillaire par les Sandox !
Bon spectre de M1. Tu a du noter que centrage et guidage sont facilités par la courte
focale. C'est pourquoi je trouve cette configuration interessente pour
l'apprentissage (aui minimum). Vive les lunettes.

Christian

(comment est le chromatisme dans le bleu ?)

[Andre Favaro]

Ce montage a été testé avec un LHIRES 600tr/mm,est-ce qu'il fonctionne avec un 2400tr/mm?

andré

[Olivier Thizy]

Le spectre est très étalé dans le bleu... un peu déçu sur le Televue sur ce coup là...

Altair au LISA

Sinon, petit changement à priori ce soir (beau temps en perspective à l'OHP): je vais tester Guide 9 à la place de Carte du Ciel car j'y suis plus habitué et il est très rapide à l'affichage. A priori, ça a l'air de causer entre Guide 9 et la monture NEQ6Pro/Ascom...

[Olivier Thizy]

Hello,


Here is a picture of my LISA spectrograph with two Atik cameras mounted on a Televue 85mm on a EQ6 mount. An electronic finder look for the field of view.

LISA + TV85 + NEQ6

web_IMG_2116.jpg (65.65 KiB) Viewed 11213 times

And a screen copy during acquisition of a spectrum of M42. One can see the electronic finder image (top right), the guiding camera field (right) and the spectrum acquisition camera (left)... All is controled in AudeLA open source software.

Screen copy during M42 spectrum acquisition

M42 spectrum is almost saturated in 120sec exposure (85mm refractor)... Note that I have switched to Guide 9 now. Easier for me to GoTo any target; I can add bookmarks (for new nova for exemple); and I can easily point the scope with Guide 9 through ASCOM interface.


Cordialement,
Olivier Thizy
Vous ne verrez plus des étoiles comme avant !
http://www.shelyak.com/en/