Search Results for 'espin telescope'

[Andy Wilson]

Hi Paul,

The telescope type is in the visual observation spreadsheet. This is quite old, dating back to the submission format for the old text file database that was created in the 1990’s when database field size mattered. Today this is not so much of a problem, but I’ve not bothered changing the spreadsheet since it is what the VSS observers are used to.

In the visual spreadsheet there is a comment if you hover your mouse of the ‘Type’ field on the ‘Observer Details’ tab. R is for reflector and G is for refractor (Glass). In fact this does not really matter and you could type ‘refractor’, ‘reflector’, ‘Meade 8’, ‘C11’, etc. The only limit on the visual spreadsheet is the total length of all the instruments must not exceed 255 characters. The database upload process checks this and will tell you if this limit is exceeded.

In the photometry spreadsheet it is the ‘Telescope Short Description’ on the ‘ObsvEqmt’ sheet that matters. This does not actually need to be very short as the description can be up to 255 characters, though if anyone uses this much text I think they are being too descriptive 😉 Examples are:

• RC 0.6m f/8
• Meade 14 LX200R on AP1200

For collaborative efforts, it is best to setup an observer code to cover all the collaborators and a special login.

Cheers,

Andy

[Dr Paul Leyland]

I’m in a curious position in that I know a fair deal about data reduction but almost nothing about submission of observations to the BAA-VSS in the modern era.  Thirty years ago observations were reduced manually, scribbled on a piece of paper and sent through the Royal Mail.

Andy and Gary have been very helpful, I’ve read the PDFs on how to submit observations and downloaded the spreadsheets (more on this in a  separate thread).  However, I’ve not yet found a FAQ covering the really basic topics.  For instance, what goes into the telescope type field?  NE is pretty obviously a naked eye observation, but is R a reflector or a refractor?  What other codes should be used?  The 30 year-old memories lead me to believe that a reflector is type T but I could very well be wrong.  Are different types of refractors (apochromatic vs achromatic for instance) distinguished?  Likewise reflectors?   What about catadioptics?

Another question is how to record collaborative efforts.  Kevin Hills, Phil Charles and I have some observations to submit and although I’ve been given the go-ahead to use my observer code it would be good to have their contributions recorded for posterity.

Other newbies may have similar questions.

The real question: have I missed finding the FAQ and, if not, should we create one?  I’d be very willing to ask questions!

Paul

[Helen Usher]

Thanks Denis 🙂  for both the data and the reference

I have time on the Faulkes Telescope and so was hoping to gather some useful data on this comet – no chance of doing it from home!

Helen

[Robin Leadbeater]

Hi John,

Don’t throw out your calibration module just yet !

There is a just detectable systematic difference between my ALPY internal lamp and the Argon “Filly Cross” lamp mounted at the edge of the telescope aperture in line with the slit but it is small (Calibrating the Filly lamp with the ALPY lamp gives +1A error around 7000A, 0 error around 5000A and -0.7 around 4100A).  

Cheers

Robin

[Robin Leadbeater]

The errors are within the FWHM of the slit image so I wonder if it could be something distorting the line profile eg :-

Coma from the ALPY camera lens distorting the line shapes more at the edges, which will depend on the f ratio of the incident light and appear as a variation in dispersion.

On stars, some sort of  chromatic aberration in the telescope optics producing a wavelength dependent asymmetry in the psf of the star which alters the distribution of light across the slit and hence the line profile.

Cheers

Robin

[John Coffin]

Method

Spectra of Zeta Cas and Z And were collected, the latter was exposed for 240s to avoid saturating the H alpha emission line and then a further set of exposures for 600s were taken in order to show more detail in the continuum and other emission lines.  Towards the end of the series taken for 600s the telescope reached the meridian and the lamp image for that set was not taken until after the meridian flip. On the other occasions the lamp image was taken immediately after the end of a capture sequence.

Results

The spectra were processed in ISIS in three different ways.

Balmer lines only

This couldn’t calibrate Zeta Cas so was not suitable for Z And either

Mixed Balmer and lamp lines calibration

Each time the lamp lines for the particular target were used.

Zeta Cas               H alpha blue shift 1 A, accurate from H beta onwards towards the UV end.

Z And (600s)       H alpha red shift 2 A, gradually increasing so at H delta the red shift was 3.4 A.

Z And (240s)       H alpha blue shift 6 A, reducing so at H delta the blue shift was 4.0 A.

In all targets using the mixed method the wavelength errors become more shifted towards the red at shorter wavelengths.

Lamp lines only calibration

Zeta Cas               H alpha blue shift 1 A, increasing so at H delta the blue shift was 4.5 A.

Z And (600s)       H alpha red shift 0.7, accurate calibration from H beta to H delta. H epsilon was blue                        shifted by 1.5 A.

Z And (240s)       H alpha blue shift 6.0 A, increasing so that at H delta the blue shift was 7.7 A.

So in all the targets calibrated by the lamp lines alone, the wavelength error shifts towards the blue at shorter wavelengths. 

I will be very interested to see the result of your Filly Dot experiment. I may have to throw away my calibration module. (I’ll keep it for the flat fields actually).

Cheers, John

[Robin Leadbeater]

OK, I have now manually calibrated using:- 

The standard set of lines used by ISIS for the automatic fit (lamp lines only)

The same set with the 3946 line removed

The set of lines used for Hugh’s calibration in post #36, less the H alpha line which I do not see in my spectrum

The calibrated star spectra were  identical every case with errors the same as  those in my post #37, within the fit uncertainty of +-0.5A, even down to 3750A  

Lamp spectra calibrated using these fits showed no significant wavelength errors so  the problem, in my case at least, appears to be caused by some systematic difference in the way the spectrograph sees the internal calibration lamp compared with the star. The error is  wavelength dependent rather than a simple offset so is going to be difficult to correct for.

I think my next step will be to check what my “filly dot” lamp, which is mounted over the telescope aperture,  gives.

Cheers

Robin

[Ron Morley]

Hi Martin

Thank you for your wise words.  I had begun to wonder if it was me who was hopelessly incompetent.  Inexperienced yes.  I also got to the stage of dreading switching on the LX200 and pressing the hand box buttons not knowing what might happen.  Fortunately even although it’s now 19 years old I have not done much fast slewing.  Now, like you advise, I perform a single star polar alignment then manually creep up on the unsuspecting target perhaps with a final auto-find when within a few degrees.  I seek relief from the trials and tribulations of the LX200 with my 12″ Dob which is fun.  I saw your 19″ Newtonian in ‘The Modern Amateur Astronomer’ book which I bought some years ago.  It was a huge beast.  I also saw your troublesome LX200 12″ in  ‘More Small Astronomical Observatories’.  Oh my, Scalextric motors.  I know them well. Like many youngsters growing up in the 1960’s I had a Scalextric set (50′ circuit) and regularly had to replace the plastic gears, clean the commutator with a pin and replace the carbon contacts.  My father had established a model/toy shop and with him being a qualified electrical fitter gave advice to me and fixed all the wonked out cars after Christmas – which were usually filled with hairy carpet.  They were frail little things and the gears (and motors) did not last long if mistreated even mildly.  Definitely not appropriate for putting in a telescope and making them whirr round at enormous speed.  What were Meade thinking.

I’ll fiddle around a bit more with polar alignment and PEC training and then go for stacking.  30 secs works ok for the brighter deep sky objects.  I attach a recent M31 image using the 60mm refractor – 21No, 30 sec exposures – possibly with dark frame subtraction (I’m learning the software) but with an unclean primary.  The Ultrastar camera is good – a smallish chip and perhaps more of a guide camera – but simple to use and give good images. 

The LX200 and webcam (Toucam Pro ii) worked ok for me back in 2009.  I attach one image of Jupiter taken on 22nd August 2009 at 23:08hrs.  Equatorial diameter 48.77″ and altitude 66 degrees.  Seeing was very good.  Image taken from location 35 miles inland from Cape Town.  Registax software used to extract and build image.  Fortunately I managed to find my old AVI video files so I can have another go at processing.  

I have some horrendous AVI files which shows that sky ‘wobble’ can be worse than mount wobble.  I will have a look at the option of a new mount in the near future.  As an aside. An LX200 lift damaged my spine in 2007.  I’d been going to the gym for 3 months was fit and relatively light in weight (for me) – mere 13 stone.  A straight arm lift of the telescope from the wedge and bang the disk bulged.  A horrible and painful 3 days spent lying flat on floor followed by a dead foot/leg for 6 months.  Even now one leg is weaker than the other.  So I can vouch for the advice ‘beware of heavy telescopes’.  

On PHD it’s not important.  It’s just another piece of software for me to fiddle around with.  It’s usually the drivers and comms protocols that confound me.  I’m not an electronic/software person (I’m a civil engineer – geotechnical) so I struggle a bit with the acronyms.  Also modern guides are a far cry from Airfix  instructions or Haynes Workshop Manuals.

Your Paramount and C14 sound fantastic.  A really high quality system indeed.  That’s a real BMW plus plus set up.  My Dad had a Morris Marina.  Worse car ever he said.  I drove it.  Oddly light and erratic.  Yup – wobbly like an LX200 mount/drive. Not like the old Austin Maxi he had previously – stable yes – but that gearbox was beyond a joke – stirring cobbles – impossible to engage first gear – three attempts minimum needed – embarrassing at traffic lights.  

I will persevere with the short exposures and stacking approach with as good a tracking I can manage with the LX200.  Tonight looks promising so I might have another go at M31 with the cleaned up primary on the 60mm.

Cheers, Ron

[Martin Mobberley]

Hello Ron,

Firstly, I don’t have any experience with PHD, sorry!
However, from 1997 to 2003 I did regularly battle with my own LX200 and faced the same dilemmas as yourself, except that I also had huge non-Go To Newtonians at my disposal.

I initially used an SBIG ST7 with a built in autoguiding chip with my LX200. The arrangement worked, BUT, was always a hassle to set up. It was far less stressful to simply take multiple 60 second (or less) exposures, especially as I mainly imaged comets that moved in longer exposures anyway. Mind you, I was never a mega-long exposure Deep Sky imager anyway. As well as comets I imaged novae, supernovae, and other objects for which a set of 60 second exposures was good enough.

My biggest problem though was with the LX200 itself. On the 2nd night of use the RA motor/gearbox failed. This was soul destroying on a brand new £5K instrument. Eventually the dealer replaced the entire telescope, but the problems continued. Once or twice a year the telescope had to be dismounted and sent back to the dealer for new motors to be fitted….. This went on for 6 years. I examined the motor/gearbox assembly and was horrified to find a (literally) Scalextric toy car motor providing the drive to the gearbox chain; the gearbox consisting of tiny plastic wheels, glued onto shafts before the final worm stage. It was this gearbox/encoder system that always failed. On full slew the motor spun at 14,400 rpm (gulp!)

After I found this out I never slewed the telescope again, just synced on a star and crawled to the right RA and Dec, or unlocked the axes and pointed the LX200 manually. Eventually I gave up and simply used the LX200 for planetary work. But I dreaded even going outdoors at night for fear of the drives failing yet again. I bit the bullet and acquired a Paramount ME & C14 at this point (2003) which has never let me down. I temporarily remounted the LX200 tube on an EQ6 but this was not a brilliant solution as the 12″ tube was a bit too heavy (your 10″ will be considerably lighter though).

I’ve gone off topic here and not really answered your questions Ron, but, suffice to say, with my own LX200 the only way I could use it without loads of night-time hassle was using multiple short exposures and never slewing at high speed. There was not enough time between breakdowns to enjoy using the system and to perfect autoguiding. Eventually I grew to really hate the telescope with a passion!

I guess what I’m saying is, a decent modern mount really is the best solution. Even a humble NEQ6 Pro is in a totally different reliability and stability league to a vintage LX200. It’s like the difference between a BMW 5 series and a Morris Marina!

Hopefully someone else can answer your PHD query.

Good luck!

Martin

[Ron Morley]

This is my first post though I’ve been a member for some time (15 years I think).  I’ve dabbled with imaging since 1999 with some success on the planets using the colour SXMX5C and then a Toucam Pro 2 webcam.  The images were taken from my 10″ Meade LX200 Classic with tripod.  This was a temporary set up.  Now I’m fortunate in having a permanent set up in a sliding roof observatory and have been slowly gathering together the ‘bits and pieces’ I purchased over the last twenty years or so.  It has been both interesting and frustrating.  Interesting to read the glowing publicity from Meade in the 1990’s about the LX200 imaging capabilities placed on wedges and what is now said about them.  I now understand the ‘wobbliness’ of the system.  The most frustrating aspect though  has been the relentless obsolescence of my equipment.  My old SXMX5C camera used Windows 98 (or 95) hence won’t work with new hardware and software.  Fortunately my old Windows XP laptop still works so I can minimise software upgrades for the meantime.  I can use the second laptop for the webcam, SkyMapPro6, Registax and Astroart and it’s pleasant being offline – it’s all gummed up now inside but ok with minimal applications and no internet. 

I have spent the last few months working steadily to establish a moderate platform for imaging – polar alignment via the drift method, worm PEC training, mounting my Takahashi 60mm on the LX200 while learning to use the new SXUltrastar for imaging.  I’ve worked through issues of dead LX200 condenser, dead buttons on the hand box, assorted driver incompatibilities.  As I read somewhere – astro-imaging is work.  I’ve had some kind advice from David Arditti – hugely appreciated – and a morale booster.   

Anyway to my question(s).  I wish to do wide field imaging with the 60mm then later try small galaxy imaging with the LX200 putting on the focal reducer to get it down from f10 to f6.3 – subject to figuring out how to get focus with the micro-focuser attached while not incurring image train flop.  I have got my old Toucam Pro ii working ok and possibly the mount using PHD for Windows (XP version).  Can I guide with the webcam?  Are their ‘bits’ that can make image and guide star location easier without resorting to undoing the attachment screws of the piggybacked 60mm?  I think my system is cross-eyed the way it keeps pointing erratically. Is the Meade pier and wedge set up just too wobbly?  Can adaptive/active optics – like the SX attachment help with the mount?  The latter is expensive and perhaps for later on.  

I’ve had reasonable results with the Ultrastar in imaging M31 – 21No. frames of 30 secs stacked.  How far can short exposures and stacking overcome a wandering worm and hard to polar align mount?  I’ve read that a decent mount is so important and really is the only solution.  However I don’t wish to dispense with the set up I have.  My old book on imaging of 15 years back shows nearly everyone using an LX200 – and producing some decent images too.  And the LX200 is an easy to use visual telescope.

Sorry about this long note.  I could write a lot more of the challenges of struggling to achieve a decent imaging set up.  On a positive note – webcam imaging of Jupiter, Saturn and a partial eclipse was really easy to do.  But these were ‘snaps’ of course.  I hope someone can advise on webcam guiding and if the Classic LX200 communicates ok through PHD. The latter has indicated webcam and mount are ‘connected’.  I have not yet moved to the PHD ‘Calibration’ stage.  I’m waiting for a clear night to try.  

Cheers, Ron (Morley)

[David Scanlan, FRAS]

Hi all,

Spending this weekend in Belgium and France on a world war 1 tour. 

Moon is beaming down and I’m reminded that H P Wilkins claimed to observe the moon through a small telescope he took to the trenches during the war So in his memory here is a very poor photo taken with an iPhone tonight in memory of the man himself

Attachments:

1. 

   E50E49AD-477A-4D72-99A6-3BCC10C672FB.jpeg
   

[Robin Leadbeater]

Now confirmed as an Fe II nova by Wiliams et al  from a spectrum taken using the  Liverpool Telescope. 

http://www.astronomerstelegram.org/?read=12138

(My spectrum taken a day earlier is also referenced there)

Robin

[Andy Wilson]

There have been some posts to the BAA forum and members have contacted me directly to express a desire for the BAA holding a spectroscopy workshop. I’ve discussed this with a few people, but before going very far with any planning I thought it would be a good idea to ask interested members what they would like to get out of a workshop.

Please note these workshops would be about helping members with the practical aspects of spectroscopy rather than presenting results.

Here are some ideas on what could be covered:

• Processing spectra with ISIS, BASS, and possibly other software if experienced users could be found to run those sessions. While we covered ISIS at the recent Spectroscopy and Photometry Workshop, there could be some benefit from a longer follow up session. Members could bring their laptops to these sessions, and we then work through a practical example using sample files. Each session would cover a single software package and might last half a day. So we could spend half a day on ISIS and half a day on BASS. Though maybe people would prefer a whole day on a single package?
• Advanced processing techniques such as flux calibration, line measurement techniques, correcting for interstellar extinction.
• Setup and use of spectrographs. Initial setup of spectrographs is best done indoors rather than at a telescope, so it may be possible for members to bring their spectrographs to a session if we have an appropriate venue where spectrographs can be setup on tables. More detailed problems may be harder to address without visiting individual observatories, but a discussion session with experienced observers could help to address specific points. Also there are a range of spectrographs in use by BAA members, so it may be necessary to limit sessions to specific spectrographs such as the ALPY, LISA, Lhires III, L200, or other designs where expertise is on hand.

My initial thought is to have 2 or 3 one-day workshops dedicated to different topics. One day workshops are easier to organise and cheaper, noting the workshop(s) would be organised and run by volunteers. For example we could have one workshop on spectroscopy software, and another on setting up and optimising spectrographs.

To make it easy for attendees from a wide range of locations to attend, probably hold the workshops in London or a central location with good transport connections.

These are just some ideas, so please feel free to make different suggestions. Also if anyone has any good suggestions for easy to reach venues or would like to volunteer to help out with expertise or in the organisation then please let me know.

Best wishes,

Andy

[David Basey]

You could try this method based on one I’ve used in the past to find the balance point of a telescope tube.

1. Fit the telescope to the wedge and stand it on the floor.
2. Slide pencils in from opposite sides, level with each other, effectively making a see-saw.
3. Slide the wedge back and forwards on the pencils until it is in balance.
4. The vertical plane through the pencils now contains the COG.

The only issue you might have is if the COG lies outside the wedge and it tips over when placed on the floor. In this case you could attach an outrigger to prevent tipping before putting the mount on the pencils. As long as it is light in weight compared to the scope it will not materially shift the COG. After all it will shift in use if you switch from say a light eyepiece to a heavy camera.

Just a thought.

David

[David Arditti]

This reminds me of the visit I recently made to Berlin, for the European Planetary Science congress. On the last day there was a visit to the longest refractor in the world, the Archenhold Telescope, which has a focal length of 21m and aperture 68cm (f/31). The longest eyepiece they have is 100mm, giving x210. This is the power they nearly always use. The telescope is in regular use for public observing, particularly by school groups. The eyepiece is the green bit in the photo.

[Tim Haymes]

I have received a request from Bob Argyle (researching double stars) to observe a lunar occultation of 104 Tau on October 28th at 02h.  (see table ).   This is Aitken 1934 (ADS 3701). A close double star unresolved by speckle interferometry 1983.93.

A planetary camera, video or a mobile phone recording at 25 to 30 fps (or faster ) through a telescope will be helpful in attempting to confirm a companion. The recording of the reappearance dark limb (RD) could be a step-wise egress which would then indicate the secondary star. A method used by lunar occultation observers. The star is magnitude 4.9

The occultation isn’t observable from S/SE UK (Greenwich), but a graze on the bight limb (or miss) is expected in this area. Observers north of Birmingham will see the reappearance on the dark limb with the star being further from the Southern cusp.

The Lunar Section will be please to receive reports of this occultation.

Reading and Greenwich – no occultation ( approximate UT )
Table:
Location        Ph    UT   Cusp Angle
Oxford           RB 0231  bright limb
Birmingham   RD 0237  CA 3 S
Manchester   RD 0241  CA 15S
Leeds            RD 0243  CA 17S
Carlisle         RD 0246  CA 20S
Edinburgh    RD 0248  CA 30S
Aberdeen     RD 0252  CA 35S

Tim Haymes
Lunar Section (Occultation group)

[Denis Buczynski]

Hello all,

Talk of large eyepieces made me think of the thread on Antique Telescope Forum about the Great Melbourne Telescope and the low power eyepiece used on it. Here is a picture of the eyepiece with a field lens of 8 inch diameter! That is a large eyepiece.

[Robin Leadbeater]

Some more information on the request for spectra of X Per from Dr Paul Roche, CardiffUniversity, announced here

https://britastro.org/node/15515

X Per is an X-ray binary where material from a Be star disc accretes onto a companion neutron star. It is Vmag 6.7 so bright enough for high resolution spectra.

It is not in BeSS currently as it is not considered a “classical” Be star system but if anyone currently monitoring Be stars could add it to their list he would be grateful. He is looking initially for high resolution H alpha spectra to monitor the state of the disc. Spectra can be added to the BAA database and any changes in disc state seen should be announced here or direct to Paul or me.    More information from him below

Cheers
Robin

He writes:-

I’d like to (re)start a monitoring programme on the Be star X Persei, the optical counterpart to the X-ray pulsar system 4U0352+309. This is an unusual X-ray system, with a slow pulsar (~14 mins spin period) in a wide binary (~250 day) orbit, which exhibits phases where the Be star loses it’s circumstellar disc (characterised by unusally faint periods where the primary fades to V~6.9-7.0). X Per is generally a bright B0e star (V~6.4-6.7), and I’m interested in setting up a long term monitoring project to try and follow the system through it’s next disc-loss phase. 

I did this in the 1990s (as part of my PhD) and it was very successful, and with the growth of amateur spectroscopy I’m keen to see if we can keep tabs on the behaviour of the H alpha line as well as on the photometric behaviour, as this line is a strong indicator of the state of the circumstellar disc that gives the Be star it’s “e”.

In BeXRB systems (and X Per in particular) the H alpha emission and IR excess are exactly as would be expected from a standard Be star, and the neutron star accretes from passage through the outer regions of the disc (leading to transient emission), so a system like X Per can be considered and monitored in exactly the same way as a single Be star. Changes in the disc have an impact on the X-ray behaviour of the system, as the neutron star is influenced by changes in the size and density of the disc (which is where it occasionally accretes, once the disc reaches the distances of the neutron star orbit). So monitoring the disc emission provides a clue as to the future behaviour of the X- ray source, and I’m hoping that a monitoring programme can help predict X-ray emission when we start to see signs of disc growth and then loss.

Ideally I’m looking for as much UBVRI photometry as possible over the next few years, with any H alpha spectroscopy an added bonus. The system has long period variability, but short period (minutes) changes in both photometry and spectroscopy have been noted previously. I’m going to be setting up a monitoring programme using the Faulkes Telescope Project (via the Las Cumbres Observatory facilities, mainly the 0.4m ‘scopes in the network as this is a bit bright for a 2m!), but having additional data would be fantastic and would be really valuable in helping to monitor the overall system on timescales of weeks-months-years, and correlate with X-ray behaviour in particular.

H alpha line profile and the overall spectral shape, and/or just the EW of H alpha, would be useful – H alpha (as high res as possible) is really what I’m after at this point as it’s usually the best indicator of disc behaviour, but any data that can be gathered would be great. I’m hoping to get a Masters student to look into all of this over the next year, and then each year after that, as it seems to be an unusual system even amongst the Be stars, and also amongst the BE/X-ray systems!

Dr. Paul Roche
Cardiff University
Faulkes Telescope Project

 

[Tony Rodda]

Hi guys,

Where’s the best place to advertise spectro gear?  (Gratings, prisms/wedges, mirrors, lenses, fibres, beamslitters, etc).  Some of the parts obviously lend themselves to telescope/guider building but generally they’re quite specialist.  About three dozen bits and bobs (some new and still sealed) that I acquired a year ago and are surplus to my current efforts. Most are Thorlabs, Edmunds, or Optimetrics but I’ve a bundle of new Surplus Shed lenses too.

I detest Ebay but UK BuySell seems to be mainly ‘telescope/mount’ orientated.

Anyone got any experience?  Any ideas welcome.

Regards

[Gary Poyner]

Dr. Paul Roche, Cardiff University and Faulkes Telescope Project, has just posted a request on BAAVSS-ALERT for photometric observations and H-alpha spectroscopy of the bright Be star X Persei.  You can see the full message here

Thought there might be a few observers here who might be interested in taking part, who wouldn’t have seen the alert message.

Good luck,

Gary