First crack at photometry

[astrogardener]

I've been slowly piecing together my 'rig' for my foray into variable star photometry.

I've made nearly 9000 obs visually, but now I'd like to concerntrate on fewer stars with higher precision.

I had to replace my old hand made alt-azimuth with a shiny new NEQ6, learn how to use EQMOD, CDC, MaximDl etc.

I'm hoping my old Helios 6 inch refractor+ V filter +SBIG  ST7 (nabg) will be a good combination. I'll get a 19.7 x 13.0 fov @ 1.55"/pixel.

My first star will be (clouds permitting) V369 Per, a YSO star I've followed visually for a couple of seasons. It has a range of around 9.5-12 mag. With this set up I'm hoping, as my experience grows, to follow up on Nova discoveries, and maybe add another filter or two.

I'll keep you posted.

Doug.

[petek314]

I have done some variable star observing but no where near as much as you. I was hoping to try and do photometry but I have a DSI IIc colour camera which apparently is not ideal. It will be interesting to see how you get on with this and how accurate your measurments are. Good Luck, Pete

[astrogardener]

Cheer's Pete,

Yes, just waiting for the weather to cooperate now.

It's going to be quite a learning curve, I've studied all the tutorials I can, now I've just got to put it all in to practice.

It's a shame your DSI II isn't mono, I think it would have been suitable for photometry. I know that there's a few guy's working with DSLR's by

using just the green channel, that would be an another option to get into photometry.

Doug.

[petek314]

I don't know how valid the results would be but I was wondering whether I could use the Star Analyser and just read the magnitude obtained at the V frequency. I think I will have to experiment!

[astrogardener]

I don't know how valid the results would be but I was wondering whether I could use the Star Analyser and just read the magnitude obtained at the V frequency. I think I will have to experiment!

Pete,

I'm not sure, the AAVSO have a forum dedicated to Spectroscopy, some very interesting topics well worth a read.

Doug

[StarryEyed]

The AAVSO has a great document on using a DSLR and CCD cameras it is a treasure trove of information as well as citizen science pages which they have taken ownorship off. They have many otjer specilist groups.

The BAA also has some documents about CCD work sp thats a must look also.

There is plenty there to get you up and running.

Any CCD camera can be used as lomg as you work out how linear it is and I know that plent of of anti blooming chips are very linear plenty enough for photometry.

[Tony Rodda]

Yes, the BAA VSS has some great "How to" docs for download.  Also a spreadsheet that automatically derives measurements, etc.  It outputs the text files for auto submission to both BAA and AAVSO.

The software package "AIP4WIN" comes with a book that goes into some detail about calibrating your images extracting magnitude measurements from frames.  It also has tutorials on photometry and how to produce light curves, etc.

I'd recommend joining the BAA.  they'll appoint a mentor and you'll get tons of help.

Best of luck.  It's very rewarding.

Regards

Tony

[Merlin66]

You can't just "read" a V mag from a lo-res spectrum......you need to apply all sorts of corrections etc.

[Perseus_m45]

I have had interest in this myself. i'm going to keep up with this tread thread..

                                                                                                                              mike h

[berkonights]

I just rejoined today after a 5 year gap visiting this site. Now I do all my imaging remotely using equipment I have installed at astrocamp atop a mountain in Spain. Mostly I do deep sky stuff, but I had one go at photometry with the help of a friend to process. I'm keeen to do collabrative projects if anybody else is? I have a Stellavue 102ED with televue flattener on Paramount MX mount, QSI 683wsg with 8 filters, lodestar for off axis guiding, lakeside electronic focuser, kendrik dew heater. s/w Sky X6, maxim DL, ccdautopilot professional, ccd navigator3, photoshop etc.

I have on order a Takahashi 150 which should be up and running by the end of May 2014.

so would love to do some collabrative stuff, binary star stuff and eventually exo planets. let me know.

attached is my first and only results, which show good correlation to the established data.

[astrogardener]

Thank's for the comments.

I've recently been using an 8" ritchey chretien with the ST7.  I've been able to get good data down to around mag 16, this has been great for monitoring CV's and R Crb type stars, R Crb itself is faint at around 14.5

Currantly I'm participating in a project to monitor SN 2014G, a type II supernova https://edocs.uis.edu/jmart5/www/barber/sn2014g.html

And back in January I was able to revisit supernova Eridanus 2009 (KT ERI) still shining at 15.2, and variable between 14.5 and less than 15.2.

For the brighter objects, one star I followed all winter for another campaign was the T Tauri star BP Tau, this was a request through the AAVSO for data on this star for an upcoming project with the Chandra X-ray telescope.

And another supernova in Ursa Major I'm following is SN 2014J, in M82.

With modest equipment it's pleasing to be able to contribute useful data.