andrew s

My run off roof observatory is a sad sight emptied of all the kit and left draped in the cobwebs I always intended to remove. It has been an effort over more years than I care to remember populating it with mounts, telescopes and various instruments. It now sits idle and unloved. Potential fire wood. But, wait the kit sits neatly packed ready to go to a new home in southern Spain. The promise of 200 plus clear nights a year rather than the 10 or so I get in the cloudbank that is the Cheshire gap. Sunday will see the start of an adventure to load the car (very full) and set off to Eurotunnel... ...to be continued. Regards Andrew

Looking much more like it. I am slightly puzzled as to why your zero order is not at zero. What order fit are you using? As Robin points out it should be close to linear so I would use a linear fit or a 2nd order at most. I suspect you line 06 is teluric in origin that is from our atmosphere. Regards Andrew

Robin is right about ISIS but I think this is historical. I am not aware of any technical problems with BASS which would disqualify it from serious work. I have used IRAF, ISIS, Visual Spec, Rspec and BASS unless someone can point out specific problems with BASS for basic slit or slitless spectroscopy that's what I would recommend to new users. Regards Andrew

Looks like the calibration is out. What you have identified as H alpha is most probably H beta. Nearly there. Regards Andrew

I have used both. Unless you want to do real time spectra then I think BASS is the better package. Regards Andrew

Probably one you can't lift or aford. More seriously anyone that let's you enjoy our hobby. Regards Andrew

I particularly like the second image @ollypenrice a true work of high art. Regards Andrew

Yes you can especially with a slit spectroscope. You can subtract the "sky" background which will remove moon light, sky glow and general light pollution . Without a slit you can still do sky subtraction it but it is not quite so effective. Regards Andrew

In my view using two CCD cameras and one CMOS with the right technique you can make either perform to a very high level. It is easy to forget that modern CCD and CMOS chips are miles ahead of those just a few years ago. I doubt either your current CMOS camera or the proposed CCD will limit what you can achieve. Regards Andrew

Welcome Tracy. Any thoughts on what you want to observe? Regards Andrew

I think this is a real possibility. They may also share proper motions with local cluster stars giving an estimate though this might be difficult to pln down. Regards Andrew

...music of the spheres. Regards Andrew

With Rspec it gas a feature to do it in real time. Other than that it's trial and error. Inspecting images as you go. Regards Andrew

Louise, having focused on the star, as Robin advises, you will need to tweek the focus in (I.e. towards the objective or mirror) due to the geometry of the diffraction. It's not very much so easy does it. Regards Andrew

It's in Science - Radio Astronomy and Spectroscopy Regards Andrew

I don't think all CCD or CMOS chips can be discussed effectively by category. You have to consider each one and how it is packaged individually. I know of one CCD that added fringes to high resolution spectra but not others. Some CMOS cameras have more amp glow but I recall the days when CCD cameras had the same issue. CMOS is where the research and development money is going so consumer CCD will be a thing of the past in a few years. Even NASA is using a CMOS camera on one of its solar missions. Look at each offering and how you want to use it objectively then decide. Regards Andrew

I think it depends on the atmosphere inside the dome. If the temperature is below the dewpoint for the dome atmosphere on any surface in the dome then dew will form on it. If you go to the trouble to ensure the dome is close to the night time conditions for good seeing then dew will be more likely . Regards Andrew

Yes indeed a noteworthy project. Can the roof shut whatever the telescope is pointing? Regards Andrew

Also done in software for CMOS camers after downloading. Regards Andrew

Is it a closed tube? The only things I can think of are stray light or reflections. Regards Andrew

How are you taking them?

No this is not normal. Is the centre over exposed? You should not see a shadow of the secondary but I doubt that is what you are seeing. It should look like another flat brighter in the middle with some vignetting towards the edges. Regards Andrew

I assume you mean last Friday of the month not week 😀

Chester AS have a meeting tomorrow night. See chesteras.blogspot.com I hope to get back from grampa duty in London for it. Regards Andrew

I am generally not a society type but joined the Chester Astro soc. I find them very friendly and welcoming. It has a mix of armchair and real observers with a fine line up of speakers. Regards Andrew