G.N. RajasekharaGirish Kumar Beeharry

Mauritius Radio Telescope

The CALLISTO spectrographin Mauritius

Outline

· First Antenna· Back end· Commissioning· First flare· Subsequent flares· Observations from other CALLISTOs· Future work

The First Antenna

Broad band logarithmic periodicantenna at MRT site.The antenna was built out ofstandard aluminum profiles in thelocal workshop.Frequency range goes from 20MHz up to 860 MHz in fixedvertical positionVertical tubes on both sides are made of PVC to mechanically support long, heavy dipoles..

The Back End

The CALLISTOspectrometer is on the left side of the table(below ‘TobleroneChocolate bar), powersupplies just behindand monitor withkeyboard and PC on the right.,

Commissioning (27.04,2009)

X-axis shows time expressed in UT, Y-axis frequency in MHz and Z-axis denotes the stored digital value of the ADC(without any calibration).The frequency resolution is ~ 4 MHz and time resolution is 250 msec (4 sweeps Per second).Data is stored in 15 min FITS files

Quiet Sun: with background (08-10-2009)

45 MHz

860MHz

15 minute time interval (UT)

Quiet Sun: background subtracted(08-10-2009)

45 MHz

860MHz

15 minute time interval (UT)

Active sun having sunspots: with background (24-09-2009)

45 MHz

860MHz

15 minute time interval (UT)

Active sun having sunspots: with background subtraction (24-09-2009)

45 MHz

860MHz

15 minute time interval (UT)

Zoom in Active sun having sunspots: with bkgrnd subtraction (24-09-2009)

45 MHz

860MHz

15 minute time interval (UT)

“First light” flarZoom in Active sun having sunspots: with bkgrnd s092009)e ( 2009)

Mauritius

45 MHz

860MHz

15 minute time interval (UT)

45 MHz

860MHz

15 minute time interval (UT)

“First light”close up May 1st 2009Mauritius

Solar flare (6th May 2009)Mauritius

45 MHz

860MHz

15 minute time interval (UT)

Solar flare (8th May 2009)

Mauritius

45 MHz

860MHz

15 minute time interval (UT)

Zoom in Solar flare (8th May 2009)

Mauritius

45 MHz

860MHz

15 minute time interval (UT)

Solar flare (8th May 2009) other stations

Bleien Humain

Solar flare (8th May 2009) other stations

Kasi Mauritius

Solar flare (8th May 2009) other stations

Ooty lin pol1: Lightning flash at 08:09:01.5 UT

Ooty lin pol 2:Lightning flash at 08:09:04 UT

Zoom in Solar flare (24th Sep 2009)

Mauritius

45 MHz

860MHz

15 minute time interval (UT)

Future Work

Antenna array: improved gain & sky coverage Calibration Timing experiments - Software development

Excellent first instrument for radio astronomy: Interested?