Category Archives: Photometry

Galactic Nova ASASSN-17gk

Posted on May 18, 2017 by Paul

Nova ASASSN-17gk (ATel #10387) was confirmed at Shenton Park Observatory using the ALPY 600 at R~530. This very bright nova in Centaurus is near maximum and was easily identified with a 600s exposure. Further detail kindly provided by Prof. Steve … Continue reading →

Posted in Photometry, Spectroscopy | Comments Off on Galactic Nova ASASSN-17gk

Deriving new colour and magnitude transforms using ‘Transform Generator’

Posted on March 20, 2017 by Paul

Changes in the optical train at Shenton Park Observatory together with a renewed 2017 AAVSO transform campaign have prompted revisiting photometric B and V band transformation coefficients. The addition of an AAVSO sequence for the southern hemisphere cluster NGC 3532, … Continue reading →

Posted in Photometry | Comments Off on Deriving new colour and magnitude transforms using ‘Transform Generator’

Nova Sgr 2016d

Posted on October 27, 2016 by Paul

A second nova this week, confirmed in a spectrum taken with the target setting in the western sky on October 27. The ATel (also kindly prepared by Steve Shore) can be found here: (ATel #9678). A follow up ATel hinting to … Continue reading →

Posted in Photometry, Spectroscopy | Comments Off on Nova Sgr 2016d

Determining photometric transform coefficients

Posted on July 30, 2013 by Paul

The following summarises attempts to determine magnitude and colour transform coefficients for photometric projects (using the “UBVRI” colour system) undertaken at D21. The first attempts use Landolt equatorial fields near transit, which have since been found to contain some errors in published values, … Continue reading →

Posted in Photometry | Comments Off on Determining photometric transform coefficients

Southern RR Lyrae period analysis

Posted on June 30, 2013 by Paul

Seven RR Lyrae variable stars were imaged over 4 nights spanning 12 June to 19 June. Targets were chosen with ‘all night’ viewing potential, to maximise data collection over a single night.

Posted in Photometry | Comments Off on Southern RR Lyrae period analysis

Differential photometry analysis using MaxIM DL

Posted on June 11, 2013 by Paul

The following analysis investigates the accuracy of magnitude measurements using MaxIM DL’s information tool in aperture mode, by plotting instrument magnitude against published magnitude for a Landolt field.

Posted in Photometry | Comments Off on Differential photometry analysis using MaxIM DL

An aperture photometry test using MaxIM DL and UCAC3

Posted on May 30, 2013 by Paul

Non photometric catalogues are notoriously unreliable, but are increasingly used by novices amateur astronomers using commercial software such as TheSky and MaxIM DL. The following basic magnitude ‘measurement’ test shows results using MaxIM DL’s photometry tool, unfiltered images of a random field of stars, … Continue reading →

Posted in Photometry | Comments Off on An aperture photometry test using MaxIM DL and UCAC3

Testing the linearity of the KAF-16803 CCD sensor

Posted on May 10, 2013 by Paul

Testing the linearity of the KAF-16803 sensor (the anti-blooming version of Kodak’s KAF-16801) seems to reveal a workable photometric range of up to 50% of the sensor’s full well capacity and a ‘comfortable’ upper limit of 40,000 ADU.

Posted in Photometry | Comments Off on Testing the linearity of the KAF-16803 CCD sensor