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Symbiotic mira R Aqr (M7e+) near minimum with Star Analyser 100

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#1 mwr

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Posted 21 September 2019 - 12:52 PM

Photometric data and spectrum were aquired on Sept. 20 /  2019 /  UTC 21:20. I'm not sure about the quality and validity of my measurements because I'm using low budget equipment. It would be nice to see some high resolution spectra and CCD photometric data for comparison.

 

Symbiotic mira R Aqr near minimum
 
Symbiotic mira R Aqr near minimum with Star Analyser 100

  


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#2 robin_astro

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Posted 21 September 2019 - 05:20 PM

Nice work.

 

Spectroscopy of symbiotic stars is a particular area of Pro-Am interest for some members of the ARAS forum and only needs relatively low resolution. There is a dedicated section on it here

http://www.spectro-a...wforum.php?f=37

and you can find many amateur spectra in the ARAS database 

http://www.astrosurf.../Symbiotics.htm

and in the BAA database

https://britastro.org/specdb/data.php

 

Here are a couple of recent spectra of R Aqr for comparison from the BAA database

on 2019-9-12 at  R=1100 by Woody Sims 

https://britastro.or...php?obs_id=4778

and  the H alpha region on 2019-08-27 at R=14000 by James Foster

https://britastro.or...php?obs_id=4744

 

Cheers

Robin


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#3 mwr

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Posted 22 September 2019 - 01:58 AM

Nice work.

 

Spectroscopy of symbiotic stars is a particular area of Pro-Am interest for some members of the ARAS forum and only needs relatively low resolution. There is a dedicated section on it here

http://www.spectro-a...wforum.php?f=37

and you can find many amateur spectra in the ARAS database 

http://www.astrosurf.../Symbiotics.htm

and in the BAA database

https://britastro.org/specdb/data.php

 

Here are a couple of recent spectra of R Aqr for comparison from the BAA database

on 2019-9-12 at  R=1100 by Woody Sims 

https://britastro.or...php?obs_id=4778

and  the H alpha region on 2019-08-27 at R=14000 by James Foster

https://britastro.or...php?obs_id=4744

 

Cheers

Robin

Thanks Robin! 

I wasn't aware of the huge Pro-Am community in spectroscopy. The links are very helpful. After trying some deep sky and planetary photography I'm definitely hooked. What is your recommendation for venturing beyond the SA100? ALPY or LHIRES? 



#4 flt158

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Posted 22 September 2019 - 07:55 AM

I only have one question:

How faint is R Aquarii at minimum, i.e right now?

 

M7e+ suggests a very red star. 

 

Aubrey (flt158).



#5 robin_astro

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Posted 22 September 2019 - 08:09 AM

What is your recommendation for venturing beyond the SA100? ALPY or LHIRES? 

They are quite different so it depends largely on where your interests lie.  (I have both and they complement each other)

 

The ALPY is the natural successor to the Star Analyser and is an excellent low resolution instrument giving a similar spectral range and sensitivity but at typically ~4x the resolution and with the added advantage of being able to record extended objects. It is very stable and generally needs no ongoing adjustment once set up. It is best matched to a fast focal ratio of around f5-6 which can be an advantage or disadvantage (You need to use a focal reducer with SCT which introduces chromatic aberration)  If going for the ALPY get the core module and guider as a minimum. The calibration module is nice to have but there are alternative solutions 

 

Although you can use the LHIRES at low resolution the ALPY works better. The LHIRES is really for higher resolution work looking at the shape of individual  line profiles on bright targets which is what it was designed for and is still the highest resolution spectrograph around for the amateur.  I find it is rather like a racing car in comparison to the ALPY in that it needs frequent tuning to keep it performing well. It needs a focal ratio of around f10 so is well matched to  typical SCT

 

Other options are 3D printed self build eg the LowSpec or currently being developed, the very interesting all reflective design UVEX which gives good performance over a wide spectral range. Both can be run at different resolutions. I will add the links to these if you are interested

 

EDIT links added

 

lowspec   https://www.thingive...m/thing:2455390

 

UVEX  http://www.astrosurf...EX_project_us/ 

            http://uvex30.000web...r-spectrograph/

 

Cheers

Robin


Edited by robin_astro, 22 September 2019 - 08:39 AM.

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#6 robin_astro

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Posted 22 September 2019 - 08:35 AM

I only have one question:

How faint is R Aquarii at minimum, i.e right now?

 

M7e+ suggests a very red star. 

 

Aubrey (flt158).

Yes very red. V mag 11.0  I mag 6.0 currently

https://www.aavso.or...lts/?star=R AQR


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#7 Organic Astrochemist

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Posted 22 September 2019 - 05:01 PM

They are quite different so it depends largely on where your interests lie.  (I have both and they complement each other)

 

The ALPY is the natural successor to the Star Analyser and is an excellent low resolution instrument giving a similar spectral range and sensitivity but at typically ~4x the resolution and with the added advantage of being able to record extended objects. It is very stable and generally needs no ongoing adjustment once set up. It is best matched to a fast focal ratio of around f5-6 which can be an advantage or disadvantage (You need to use a focal reducer with SCT which introduces chromatic aberration)  If going for the ALPY get the core module and guider as a minimum. The calibration module is nice to have but there are alternative solutions 

 

Although you can use the LHIRES at low resolution the ALPY works better. The LHIRES is really for higher resolution work looking at the shape of individual  line profiles on bright targets which is what it was designed for and is still the highest resolution spectrograph around for the amateur.  I find it is rather like a racing car in comparison to the ALPY in that it needs frequent tuning to keep it performing well. It needs a focal ratio of around f10 so is well matched to  typical SCT

 

Other options are 3D printed self build eg the LowSpec or currently being developed, the very interesting all reflective design UVEX which gives good performance over a wide spectral range. Both can be run at different resolutions. I will add the links to these if you are interested

 

EDIT links added

 

lowspec   https://www.thingive...m/thing:2455390

 

UVEX  http://www.astrosurf...EX_project_us/ 

            http://uvex30.000web...r-spectrograph/

 

Cheers

Robin

As always, I think Robin has given excellent advice. However, I think there is a relatively large animal in the room that hasn't been addressed: an observatory. When I went to the spectroscopy conference in New Mexico this year Francois Cochard from Shelyak asked how many people present had an observatory and more than 90% of the hands went up (not mine). I thought it was amusing at the time but I've come to realize it's no coincidence. 

 

I have an Alpy and I love it and I would use it much more often if I could, but I have found that given kids, work and weather that opportunities are infrequent to take everything out, cool down the camera and telescope, polar align, calibrate PhD, center and acquire spectra of both the target and a reference star. An observatory would greatly expedite this process and I highly recommend one. 

 

I think your current setup is quite interesting. Do you use the flip mirror on the Vixen? I found that the temptation with the Alpy was to go for greater aperture and light gathering capability. This increased time and effort to ensure good guiding. Perhaps by keeping the telescope small, you could stick with your EQ-5 mount, which I presume you find easy to polar align and guide with.

 

For now, my Alpy and 8" scope wait for better weather and I am often observing during a break in the clouds with a 55mm refractor, a Star Analyzer 100 and CMOS camera. I'll post on another thread so you can see what that looks like.

 

Good luck.



#8 mwr

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Posted 23 September 2019 - 12:04 PM

An observatory would greatly expedite this process and I highly recommend one. 

 

I think your current setup is quite interesting. Do you use the flip mirror on the Vixen? I found that the temptation with the Alpy was to go for greater aperture and light gathering capability. This increased time and effort to ensure good guiding. Perhaps by keeping the telescope small, you could stick with your EQ-5 mount, which I presume you find easy to polar align and guide with.

 

An observatory would be really great to have. But the kids need all the space in our garden for playing soccer and my spouse is non-understanding. So I'm afraid I have to wait for retirement until this dream comes true....

 

I'm using the flip mirror on the Vixen quite often to get also a visual impression of the spectroscopic objects . But I had to learn that 4 inch aperture under a suburbian sky is not really helpful for this purpose. I'm quite content with the EQ-5 (although initially  I had some problems with static friction that I could solve by imbalancing the mount).

 

Good to hear that you are using with success the ALPY system. Certainly my next investment ....

 

PS: I like your profile photo. I think the molecule is retinal?



#9 Organic Astrochemist

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Posted 23 September 2019 - 06:26 PM

Please follow Robin’s good advice and get the ALPY base unit and the guiding module at a minimum. I also have the calibration module and would highly recommend it.

You are correct about the retinal; it seems pretty important to my enjoyment of astronomy.

You and I share a lot in common: same age same profession and same interest in astronomy and spectroscopy. Even our spouses seem similar :)
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