Preliminary RCT color image of M82 and SN 2014J

m82color4cor2The above image was processed from 4 individual frames in B, V, R and H-alpha selected from among those taken in the ongoing monitoring of SN 2014J. The supernova can just be seen against the galaxy background below and to the right of the center of M82. Click on the image to see an enlarged view.

RCT PHOTOMETRIC CALIBRATIONS

Accurate calibrations for RCT photometry have been determined and will shortly appear in the Astronomical Journal (Strolger et al. 2014, in press), as shown in these excerpted filter response curvesrctfiltercurves and zero points. Click for a sharper view of the figure or table.

 

zeropoints

ACTIVE GALAXIES

A-BlazarJet-lg

Blazars and other galaxies with active nuclei have been a significant focus of RCT research, as queue scheduled observations have facilitated monitoring the variable energy output of these sources. These data are then combined with observations by collaborators at other wavelengths, providing a clearer picture of the behavior of the material in the relativistic jet and central engine.

ZW229WHITEa130605105crop

Composite light curve for the well-known AGN II ZW 229.015, showing data from the RCT (red),  Barth et al. (2011, yellow), and the Kepler satellite. RCT image of II ZW 229.015 to the right taken on 06/05/2013.

Best fit plot

The complete data set analyzed by Williams and Carini (2013) yields a break in the slope of the Power Spectrum Density (PSD) which implies a central black hole mass of 12 million solar masses, as shown in the above graph.

TRACKING COMETS AND ASTEROIDS

2013ev9_20130430_695

Comet P/2013 EV9 observed with the RCT on April 30, 2013. 54 120-second exposures were stacked to produce this composite. Click for sharper image.

Minor solar system bodies are a routine part of RCT observations, and  results have appeared in numerous Minor Planet Circulars. Motions up to 3.5”/min. are readily tracked.

HUBBLE’S DISAPPEARING CEPHEID — THE STRANGE CASE OF M33 V19

In this post we summarize continuing efforts to monitor the strange behavior of M33 V19 in B and V using the RCT. With the ability of a robotic telescope to do time series observations, we hope to gain a better understanding of this ‘previously-a-Cepheid’ object’s unprecedented evolutionary behavior.

In 1926, Hubble determined the distance to M33 using 35 Cepheids he discovered, one of which was his Variable 19, with a period of 54.7 days, an amplitude in B of 1.1 mag, and a mean B magnitude of about 19.6. DIRECT project observations in 1996-7 with the 1.2m Whipple and 1.3m MDM telescopes and RCT observations, together with other data, clearly show that the star’s amplitude has diminished to less than 0.1 mag, while the star’s mean
brightness increased substantially.

Below is a another figure showing photometry of a fainter nearby Cepheid from both the RCT and the DIRECT project, showing that photometric quality is comparable.

MONITORING A SUPERNOVA IN M101

SN2011fe

RCT observations of SN2011fe in M101 show the power of queue scheduled observations. The SN is circled in the above image. Diagram from Strolger et al. (2014, in press). RCT observations are shown as solid circles with error bars, while AAVSO observations are shown for comparison.  Click for a sharper view of the figure below.

sn2011felarge