Producing PR Images

One of the best ways to promote our observatory is showing superb astronomical images obtained using the ING telescopes. For this reason we encourage observers to take good PR images. Full credit will be given to the authors of the images.

• Images from the ING archive
• Some observing guidelines
• PFIP characteristics
• Targets for PFIP
• ACAM characteristics
• Targets for ACAM
• WFC characteristics
• Targets for WFC
• Reporting an image
• Related links

Images of Messier objects potentially useful for our collections found in the ING archive are:

M2, M8, M10, M17, M23, M34, M39, M44, M49, M52, M59, M61, M67, M71, M72, M77, M78, M79, M80, M84, M85, M86, M88, M89, M91, M94, M102, M108, M110.

These images should be de-archived, reduced and if the result isn't good enough then it can be added to the current lists of targets.

We aim at producing superb, colourful astronomical images of popular objects so when observing please follow the guidelines below.

1. If you are observing at ING and you have a gap in your programme (for instance, in twilight when neither science nor calibration frames can be obtained), please select an object from our lists of targets (if you have more interesting targets than could be added to the lists, please let us know).
2. Take the usual calibration frames: biases, sky flats. Take as many flats as possible. If sky flats are a few or none, then please do many dome flats.
3. When pointing, you may want to take a glance image to improve the pointing and avoid any undesired artifact or gap on the detector.
4. Exposure times should be adequate to get a good signal to noise ratio. Split the total exposure time into several short exposures, at least 3, in order to get rid of cosmic rays and to avoid saturation of the brightest objects in the field. The more splits the better.
5. Do some dithering between the exposures (around 10 arcsec) if fringing is important or if your flat fields weren't good enough.
6. The total exposure time should be the desired length plus one more exposure (one is removed later when combining the frames).
7. No binning.
8. Filter selection: try to choose B, V and R whenever it is possible. Use one or several narrow-band filters when the object shows an interesting morphology in such bands. For instance, with planetary nebulae try to use filters H-alpha (656.5 nm), [OIII] (500.7 nm) and HeII (468.6 nm).
9. Exposure time should be roughtly as follows: t_R=0.5t_B; V_t=0.67t_B. If you are observing with a new Red CCD, then the red exposure times can be even shorter.
10. Always autoguide, even if you are taking many short exposures. Autoguiding must be good enough (no elongated images please!).
11. Seeing can be any with extended objects but good or very good seeing is much better!
12. Try to choose the CCD with the best cosmetics, if choice is possible.
13. Please check that the image is well centered before starting a set of exposures and you aren't missing any parts.
14. Please rotate the field of view in order to fit the image in the detector if necessary and if possible.
15. Moon can be any but avoid pointing near the Moon!
16. Photometric or spectroscopic conditions can be any.
17. Weather can be cloudy or dusty (unless of course the signal is so poor that you can't see anything in the images...)
18. If you are observing with a mosaic of CCDs, and the object fills more than one CCD, please shift the telescope in order to cover the gaps between the CCDs.

Imaging features:
FOV: ~16x16 arcmin (9-arcsec gap), ~8x16 arcmin
Pixel scale: 0.24"/pixel
Image size: 4096*4100 (2050) pixels
Filters: Broad- and narow-band imaging.
Cosmetics: CCD2 better than CCD1.

Best for: Faint objects.

Relative Transmission Efficiency Factors:

Filter	Airmass=1.0	Airmass=1.5	Airmass=2.0
Harris B	1.0000	1.0000	1.0000
Harris V	1.3801	1.4535	1.5292
Harris R	1.4360	2.1280	2.2827