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Everything posted by jsandse

  1. Mathieu, Sorry for delay getting back to you. A working link to some of my old work is here: Go here http://stargazerslounge.com/gallery/album/754-spectra/ http://stargazerslounge.com/gallery/album/1987-be-stars/ John
  2. The IAC 80 on Mount Teide (Canary Islands) is being used for this campaign with amateurs operating the telescope. Here is a link to some spectra taken of WR134 at the IAC 80 by Thierry Garrel at a similar time to when mine were taken - they appear to agree quite with the ones I took
  3. Hi Ken, Yes its been a long time since i've appeared here. Spent all my spare time up to a few weeks ago juggling maths equations - erm studying astrophysics - and not had any time to do spectroscopy Here is a series of 1 hour exposures taken on 29th July showing the gradual filling in on the blue side of the line:
  4. jsandse

    wr134 130729 176

    From the album: Spectra

  5. Hi all, I spent the last week or so taking spectra of the 5411.52 angstrom HeII line of WR134 - it showed some quite dramatic variations in the line on a daily basis. The experts suspect this is due to corotating interaction regions (CIRs) in the atmosphere of the star. WR 134 is one of the targets for the pro-am campaign currently being run by the Convento group. I am submitting my spectra in the hope that the spectra may be useful for the campaign. Details of the campaign can be found here: http://www.stsci.de/convento/ Spectra shown below: cheers John
  6. Nice spectra gasman! - I especially like the WR134 and WR135 spectra . I have been working on WR134 myself recently. I'll post some of my spectra up on the forum shortly cheers John
  7. Afraid never used starlink so cant help with that really though there are some links on the starlink webpage that provide some onlibe help. As I remember iraf is well documented and there are user guides. Just google iraf user manual. I use ISIS software by christian buil and spcaudace software by benji for data reduction. You can find their software online easily by googling it. The advantages for using this software for the amateur are that they run on windows and have a nice user interface. Cheers John
  8. Hi all, The Stellar Atmospheres study group has been going for almost a year now and we currently have 4 participants - from UK, Belgium, USA and Germany - so it is an international group. All the participants are amateur astronomers. We have just finished going through our first book: Introduction to Stellar Atmospheres - Erika Bohm Vitense. We will be now be starting on our next book on 24th March: The Observation and Analysis of Stellar Photospheres 3rd Edition - David F Gray We have a couple of places if anyone else would like to participate in the group. If you want to participate you need to know what is expected of you: 1) You need to have a copy of the book. 2) You have a computer with microphone, speakers and internet access so you can take part in our online meetings 3) Small sections of the book are assigned before each meeting to each member of the group and each member is then expected to present on that part of the book in the meeting. The member provides me powerpoint slides or PDFs of what they want to present before the meeting to myself. 4) We meet on Sundays at 5pm GMT via the internet - we do not meet every week its every two or three weeks - basically when people can manage. The meetings last between 1 and 2 hours usually 5) The meetings are in English I can say that in my time with the group it has been fun and we are all learning a lot. Let me know if you want to join or are interested and want more info by reply. John Strachan jsandse@live.co.uk
  9. Jack, Unfortunately your spectrum doesn't have a high enough SNR to elicit much information about jupiter from it - well it was only a 10second exposure . However if you persevere and get longer exposures across the visible spectral range then you can have quite a lot of fun with Jupiter. You could for instance: - take full disk spectra of Jupiter to: - identify the ammonia and methane bands in Jupiter - derive the temperature of the planet from the thickness of the methane bands - identify Ramen scattering - and if you can take spectra of different parts of the planet you can see how the spectra changes relating to the belts,zones and storms on the planet. A lot of this has been done before by professionals but Jupiter I reckon is probably not particularly well observed at the moment as there are no probes going round it - unlike Saturn which has Cassini. In fact the next mission Juno is on its way and wont be there till August 2016 - and it doesnt have a spectrometer on it which covers the visible region from what I have read. So there must be a good opportunity to make discoveries. On its way to Saturn Cassini flew past Jupiter and captured some spectra of it which can be seen here: http://vims.artov.rm...ta/res-jup.html The papers by Karkoschka which are referred to in the Cassini web page are well worth looking at. The paper records in the process of how to take spectra of Jupiter and the other gas giants in a scientific way from the earth - and describe a good way of processing your data in order to get a nice albedo spectrum of Jupiter. As always plenty of opportunity for some fun amateur spectroscopy cheers John
  10. the spectroscopists tried to get their own section but we weren't allowed because there were concerns that not enough people would contribute to the section.......
  11. Steve, Glad you have had some success with processing the spectra. cheers John
  12. onesmallstep there are a number of pro-am campaigns on the go where amateurs can provide data. Details of Proam campaigns on the go at the moment can be found here: http://www.spectro-aras.com/forum/viewforum.php?f=2&sid=7fc61100f81010afda1a0a3200cf1582 cheers John
  13. Hi Steve, using high pass filters in photoshop is something I would keep well clear of - they will only corrupt the data you have collected. There are well documented step by step pipelines for processing star analyser spectra. I wouldn't try and create one yourself. You could try the pipeline in Christian Buil's ISIS software. Robin Leadbetter translated the instructions into English from French. This is a tried and tested pipeline and you just have to copy the steps. Links to the software and the documentation for the pipeline are here: http://www.astrosurf.com/buil/isis/quicksa/tuto_en.htm http://www.astrosurf.com/buil/isis/isis_en.htm There are other software such as spcaudace and loads of others you could also use but the ISIS for the star analyser looks very well documented. Note that ISIS has the advantage over vspec that if you have several images you want to combine you can do this in ISIS you can't do that in VSpec Also ISIS has an expert mode which allows you to use flats, darks and bias frames in your pipeline to get scientifically valid data. Out of interest some albireo spectra taken by the star analyzer are on the rspec website here: http://www.rspec-explorer.com/dslr/ cheers John
  14. Dipper, Not all of these things can be done with a spectroscopy filter such as a star analyser. The star analyser (with a camera attached) and a reasonable amateur telescope will allow you to: - measure the temperature of a star - identify some of the absorption lines in the atmosphere - measure redshifts of distant quasars fairly accurately - identify the type of a supernova (if its bright enough) The others require a high resolution spectroscope and for some of the items eg examining atmospheres on exoplanets require a really big telescope eg the keck in Hawaii or ideally the James Webb Telescope when it comes online :0)
  15. Some more then that astronomers have done: - you can use spectra to detect mass exchange between stars in a binary system (if the stars are close enough to each other that the mass flow from one star to another) - for stars with disks of material going round them such as Be stars the shape of some of the spectral lines allow you to calculate the inclination of the disk to you - you can use spectra to determine the inclination of the star to you. For instance for vega it has been shown that one of its poles is facing us - as we see the sun as a disk you can take spectra of different parts of the disk of the sun and observe the structure of the sun at different depths in its atmosphere. The nearer you take spectra to the limb of the sun the higher up in the sun's atmosphere you observe - a number of spectra of standard stars have been taken by the hubble and other space telescopes. If you then take spectra from earth you can compare the difference between that spectra and the space one to determine the elements and the amount of extinction that light has as it goes through our atmosphere - detection of starspots in some stars using molecular Titanium Oxide bands formed in them
  16. Nice slide Robin. There is also an awful lot of other important information that astronomers have derived using spectra of stars - some of it pretty mind-blowing for instance: - if star is in a binary (or a multiple) star system you can potentially get a spectra with the combined spectra of the two stars in it - and using the way the lines move in the spectra as they go round each other you can work out the orbital parameters of the stars in the system - if the star has exoplanets going round it you can determine the number and orbital parameters of the exoplanets going round it - even better if you capture the spectra when an exoplanet is in front of the star you can extract the spectra of the exoplanet by subtracting the spectra from the star when the exoplanet was not in front of it! - if you know the type of star you are looking at you can use deviations of expected intensity in some of the Calcium lines (and others) to work out the sort of material that is between us and the star! - the shapes of the lines can be used to determine details of the stellar winds in some stars - wind momentum, terminal wind velocity - the wind momentum is directly related to the luminosity of the star - from this believe it or not we can now work out the distance to the star - also the shapes of the lines will tell you if there is an inflow of material going into the star and if the star has a disk of material going round it. - high precision spectroscopy allows you to do something called astroseismology - all stars pulsate as detailed in Robins diagram - the lines in the spectra of the star move as the stars pulsate - capturing this data allows you to study the structure of the star potentially deep below the stellar atmosphere. and there is lots more...
  17. Nice spectra. Zeta auriga is a binary star - one star is K and other Is B which is where the KB comes from. This star was the subject of a pro-am campaign in 2011. Link to the campaign page below: http://www.hposoft.com/EAur09/zeta%20Aurigae/zeta.html cheers John
  18. Thanks for the info Robin - I will look forward to hopefully seeing some spectra from amateurs in the near future using the spectroscope. I have seen the Shelyak eShel in operation and it looks very impressive - however from speaking to the owner it does take quite a lot of work to get it all set up and working optimally. I know of a user who sometimes frequents these forums who is in the process of building an echelle it will be interesting to see how he gets on. cheers John
  19. This spectroscope looks pretty impressive - high resolution echelle: http://www.eagleowloptics.com/eagleowloptics.com/Home.html Anyone know anything about it?
  20. Hi Steve, nice to hear from you and thanks for the comment. And yes the spectra are captured with the Atik 314L+ - one of the best low noise cameras out there for amateurs for spectroscopy cheers John
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