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Posted by Nick Atkinson at 16:34 on 2012 Dec 08
Hi Paul,Great image and reason to spur me on. I have been having a go at M42 with the following equipment.F9 6" triplet.Astro-Physics 900 GOTOSarlightXpress H9 with their filter wheel and loadstar off axis guiderMaxim DL for image capturePHD guidingHave not got the hang of star alignment with Maxim Dl that I have only just bought so use AIP4WIN v2.Like you quite new to colour imaging and I have not got used to tri-colour processing. Looks a lot easier using a DSLR. But I do not have one of these.Looks like a clear night so will have a go with M1.You ought to have a go with M42 Best of luckNick
Posted by Gary Poyner at 12:54 on 2012 Dec 08
Very nice image Paul. Well done! Hope you’ll have a go at the nebula around the variable star RR Tau for the joint VSS/DSS project!Always have to get a VS plug in do I not? :-)Gary
Posted by Paul A Brierley at 11:03 on 2012 Dec 08
Hello Jeremy,Yes I did. I find a CLS filter works extremely well, under these light polluted skies. Sadly that’s one reason for taking up CCD and Dslr imaging.I have sent this to the DSS.Compliments of Season.
Posted by Jeremy at 10:23 on 2012 Dec 08
Hello Paul,that is a wonderful picture of M1, Paul – well done! Nice tight star images.Did you take it from Macc. or elsewhere?I trust you’ll send it to the DSS Director.Go well!Jeremy
Posted by Nick Atkinson at 19:18 on 2012 Dec 07
I am not in favor of this. The constitution of the BAA is to encourage an interest in astronomy, all well to the good. The forum should remain an area that is only available to members, there are many other areas available within the our web site. We pay good money to be members of the BAA and at the moment I am the only member on line as opposed to 63 "guests" Some may conclude that they will gain very little from membership and jump ship.
Posted by Roy Hughes at 16:36 on 2012 Dec 05
Jeremy, Thanks for the pointer. I’m up to page 4 and it looks a good read. I’ll look forward to any comments from those who know more of her history than I do.Roy
Posted by TonyAngel at 22:50 on 2012 Dec 03
Very interesting. I was at an exoplanet meeting over the weekend and rv of exoplanets was discussed. I am going to forward the link to them.
Posted by David Mottershead at 19:38 on 2012 Dec 02
HelloThe Celestron 102 is now sold, but I still have for sale the following two telescopes:Meade LX90 UHTC (the classic 8 model), GOTO mounted, Autostar hand controller, 9×50 finder scope and 26mm Meade lens, plus all original manuals. The scope also comes with a Crayford style 10:1 2 focuser, flexi dew shield and Hartman mask. Please note, the scope has a small dint towards the lower underside of the tube body, but which does effect the scope at all this is cosmetic only. Optics are excellent. £700 o.n.oSkywatcher Startravel 120mm short tube refractor telescope on EQ3-2 equatorial mount, (this is the latest version in the diamond black and white livery), the supplied red dot finder scope and the upgrade 9×50 finder scope, and complete with dual axis motor drives, manuals, slow motion controls and lenses as originally supplied. £280 o.n.oIf interested in any of the above, please contact me for more details/photos at david@dmottershead.co.uk I am selling these as rationalising my telescopes, and buying a large Newtonian reflector!!Many thanks.
Posted by Robin Leadbeater at 16:06 on 2012 Dec 01
Christian Buil has updated his spectroscopic data reduction program ISIS http://www.astrosurf.com/buil/isis/isis_en.htmto include the cross correlation algorithm he used to detect exoplanets by the radial velocity method.http://www.astrosurf.com/buil/isis/new/release.htmlThere is also a link there to an interesting presentation http://www.astrosurf.com/buil/exoplanet/exo_buil.pdf(in French) that outlines how he made the exoplanet detections and some speculations on how amateurs might be able to discover new exoplanetsRobin
Posted by Nick Atkinson at 20:03 on 2012 Nov 29
I use AIP4win.version 2 This has a 2 star method of matching identified stars. There is an automatic procedure but I prefer the manual method because any artifacts on a particular image can be discarded.
Posted by TonyAngel at 13:23 on 2012 Nov 24
I hope to confirm in a week. Coming from Spain means that I need to organise it to coincide with a few other things.
Posted by Robin Leadbeater at 13:04 on 2012 Nov 24
Just booked my place 🙂 Will probably pass on the £24 lunches though It looks like an interesting 2 days. Anyone else going?CheersRobin
Posted by Robin Leadbeater at 23:29 on 2012 Nov 21
Also back in 2005 when amateur transit detection was in its infancy and was I playing detecting transits with a modifed webcam (yes it can be done -just!), pro exoplanet hunter Greg Laughlin set up something called transitsearch. The website is still there but seems to have become dormant in 2009www.transitsearch.org.He still runs a fascinating blog though (well to me anyway) here http://oklo.org/CheersRobin
Posted by Robin Leadbeater at 23:15 on 2012 Nov 21
Hi Tony, Most of AAVSO is free. http://www.aavso.org/aavso-membershipeg you can view data, register and post on the forums, register as an observer and supply data all without paying. (I have even published in their Journal without the page fees via their partly grant funded Citizen Science project) I agree though, there is not much sign that exoplanet transits is a big thing for AAVSO. CheersRobin
Posted by Robin Leadbeater at 19:02 on 2012 Nov 21
Hi Tony,If you (or anyone else) are looking for useful things to do with a spectrograph then good groups to keep an eye on are The French based ARAS group http://www.astrosurf.com/aras/and their forumhttp://www.spectro-aras.com/forum/The German based VdS grouphttp://spektroskopie.fg-vds.de/index_e.htmand their forumhttp://spektroskopieforum.vdsastro.de/There are no British/US forums working at a similar level unfortunately but both these groups are Brit friendly ;-)CheersRobin
Posted by TonyAngel at 16:58 on 2012 Nov 21
Thank you Robin. Very good advice which I will endevour to follow. I have been reading your webpages for advise on spectroscopy. I am just waiting for the clouds to disapear – it is the rainy season in Southern Spain.Best Wishes,Tony.
Posted by TonyAngel at 16:53 on 2012 Nov 21
I will have a look. I have looked at their site before, but it would mean joining (and paying) and I already in a few 🙂 I think that the ETD has a greater number of observations and better tools, though please correct me if I am wrong. It is also free 🙂
Posted by Gary Poyner at 16:19 on 2012 Nov 21
This has just appeared on the AAVSO web site..http://www.aavso.org/exoplanet-wasp-11bhat-p-10b-dslrA nice light curve taken with a 20cm SCT and DSLR (Mike Durkin).You don’t need to be a member to view, but you do to post comments.Thought someone here might find it interesting!Gary
Posted by Robin Leadbeater at 16:11 on 2012 Nov 21
TonyAngel wrote:
Under this topic Radial Velocity will be discussed.Was:exoplanet transitsTonyAngel wrote:
Thank you Robin. Yes I had read Christian Buil’s page. As I already had the use of the SGS I was hoping that I could at least see if it could have spotted the larger doppler shift exoplanents, or failing that spectroscopic binaries just to do a proof of concept before seeing if a more expensive spectrograph could be justified. Perhaps I can just use the SGS for confirmation of exoplanet’s star spectrum, (allowing this could be contamininated by the planet). As you can guess I am rather new to spectroscopy from a practical angle.SBig claim an RV precision of +-6km/s with a 600l/mm grating for the SGS which is probably realistic (I can get down to +-1km/s with my LHIRES III under favourable conditions but that is with a 2400l/mm grating which gives ~10 higher dispersion. Entry level to just detect the exoplanet round Tau Boo which I think is the easiest is ~200m/s and Buil’s precision was around +-50m/s (Which is just 0.001A at 6000A !) so quite a tough target.Actually measuring binary star component RV can be tricky as the two spectra blend and can be difficult to separate. Here is a nice easy example, Beta Aurigae using the LHIRES at 0.3A resolution.http://www.threehillsobservatory.co.uk/astro/spectra_35.htmExoplanet measurements are more straightforward (though not easier!) as there is only one component (The contribution from the planet either from planet temperature, reflected starlight or absorption during transit due to an atmopshere can be safely ignored at visible wavelengths at least. This is the task of a future generation of exoplanet hunting space telscopes, looking for signs of life) I would say a good way of measuring the capabilities of a proposed system would be to repeatedly measure the RV of a radial velocity standard for several nights and see how much scatter you get. Then you can start beating down the variability until you are at least well below +-1km/s. You would then be ready to try for an exoplanet.CheersRobin
Posted by TonyAngel at 14:42 on 2012 Nov 21
Thank you Robin. Yes I had read Christian Buil’s page. As I already had the use of the SGS I was hoping that I could at least see if it could have spotted the larger doppler shift exoplanents, or failing that spectroscopic binaries just to do a proof of concept before seeing if a more expensive spectrograph could be justified. Perhaps I can just use the SGS for confirmation of exoplanet’s star spectrum, (allowing this could be contamininated by the planet). As you can guess I am rather new to spectroscopy from a practical angle.I will create a Topic for Radial Velocity for future discussions.
