For what it is worth I took a single B exposure on 13th. It clouded over and I didn't get any other exposures with other filters.
The B measurement was 12.104 (0.04 error).
This is pretty close to your measurement.
I seem to be the only person that has entered their data on the AAVSO website. All these measurements need to be submitted.
Cheers
This question of the B magnitude is worth investigating, given that for this SN we believe it is very 'blue', which should be evident in the BVR magnitudes. Alain Klotz, the discoverer and former amateur turned reputable pro, plots the BVR results at http://cador.obs-hp.fr/sn_tarot/PSN_J03333599-3607377/ (2.Observation Follow-up), which do show that while the B mag was fainter than the V in the early stages it is now brighter since the start of this month ... which is what I would expect.
Ivan, while your suggestions make sense (and I don't question your methodology) the end results, after full TC calibrations and extinction compensation, should result in correct BVR mags.
While I used to do only photometry, mainly CV stuff, I no longer have time for it since switching to spectrometry many moons ago, so I'm rusty in that area and obvious reasons for the B discrepancy don't readily spring to mind. Hopefully younger minds will fathom it out quicker than I can.
Cheers,
For what it is worth I took a single B exposure on 13th. It clouded over and I didn't get any other exposures with other filters.
The B measurement was 12.104 (0.04 error).
This is pretty close to your measurement.
I seem to be the only person that has entered their data on the AAVSO website. All these measurements need to be submitted.
Cheers
Terry
I managed a few shots on 13 November - though I didn't manage to take flats so my data may be dodgy.
Oops - pilot error - I've now amended these results as I had failed to set up MPO Canopus to calculate using the correct filter.
My corrected results were:
B - 12.17
V - 12.06
R - 12.09
I - 12.50
When these damn clouds move on, I'll get the LISA onto this chap and will do this properly
Pete
Last edited by pvelez; 20-11-2012 at 10:06 PM.
Reason: Incorrect reduction - I've amended the results
Data from last night (15/11/12)
I took 3 x 120 sec exposures through BVRI filters. These are then averaged and photometry performed using an ensemble of comp stars with VPhot software. Results are:
B = 12.139 err 0.042
V = 11.991 err 0.037
R = 12.027 err 0.032
I = 12.533 err 0.043
I also took a reasonable spectra at the same time. It fits a type 1a SN at 0 days very nicely.
Finally nabbed it visually with my 10" Dob on the third attempt from reasonably light polluted Christchurch.
Was just about at Zenith, and managed to hop myself over from g and h Eridani. There was a comparatively bright galaxy there with 2 stars just visible near the core. I still wasn't really sure I was looking at N1365 so I jotted down the arrangement of the brighter stars on my notepad.
Thanks to Kevin's wide field shot I can confirm I was looking at the right thing, stoked to have bagged my first SN! Will try with more magnification if I get another shot at it to see if I can discern the SN itself a little better.
Last Sunday night, I had the first clear, moonless night after weeks of cloud at my location in the southern suburbs of Sydney. I managed to capture a sequence of images of SN2012fr using my Televue 5 inch refractor and a luminosity filter. The unprocessed image at right suggests the supernova was brighter than the host galaxy on Sunday night (11th November 2012). My hunch is that the supernova must have been an easy visual target using a quality 85 mm refractor. This is because I have no trouble seeing NGC 1365 using my Televue 85 mm refractor at a reasonably dark sky location (obviously not the inner suburbs of Sydney).
The cloud partially cleared long enough for a quick look for SN2012fr in NGC 1365 tonight using a 10" Dob. The transparency was quite poor, but I was able to find 1365 with the use of charts generated by SkyTools (below). The sighting of 1365 was confirmed by the expected star patterns, but I couldn't clearly define the SN near the fuzzy core - but I was aware that something was there, though. I will need to wait for better viewing conditions to confirm it.
My weather over the last ten days or so has been the best this year, allowing me to get low-res (9.5A) spectra of this SN on four nights, one hour exposure each with a C11. I've attached a composite plot for the 10, 13, 18 and 19 November.
My spectra from earlier this evening (the red line) shows a brightning towards the blue end, so I would be interested to see if this is confirmed by BVR data.
Give us a break!
