Amateur Pulsar Observations - Joe Martin (K5SO)

NOTE: All images presented here and most of the text has been downloaded with permission from this website.

Joe has been successful by detecting two pulsars: B0329+54 and B0950+08.  He has an impressive setup as shown below.

Antenna

The antenna used at K5SO to observe pulsars.

The parabolic dish antenna is 8.6 meters in diameter and is operated at a wavelength of roughly 70 cm (436 MHz).

Horizontal or vertical polarization is remotely selectable from the telescope operating position.

Operating Position

The very impressive and enviable operating position at K5SO.

The antenna position control system means that pulsars can be tracked by the antenna for hours on end allowing integration of the received signals.  The typical observation times are up to approximately 10 hours.

System Block Diagram

Showing overall configuration of the pulsar detection system.

A very comprehensive setup !!!

The Results

The results of detection of two pulsars are given by Joe.  They are B0329+54 (approximately 3300 light-years away in the constellation of Camelopardalis) and B0950+08 (approximately 1,000 light-years away in the constellation of Antlia).

 The details of the two pulsars' ephemerides can be found on the ATNF database.

PSR B0329+54

------------------------------------------------------------------
#     NAME          RAJ         DECJ                P0      S400
                    (hms)       (dms)              (s)     (mJy)
------------------------------------------------------------------
1     B0329+54      03:32:59.3  +54:34:43.5   0.714520   1500.00
------------------------------------------------------------------

This pulsar is the second strongest of all pulsars at 400 MHz (1.5 Jy) after the Vela pulsar (5 Jy). Although Vela would appear to be an easier target, unfortunately for Joe (located at latitude 36 degrees north), Vela at a declination of 45 degrees south never reaches more than approximately 8 degrees above the horizon limiting observing opportunities at Joe's location.

Joe's results for B0329+54 using SDR14 and SpectraVue are shown below.

The SDR-14/SpectraVue display of the pulse profile from PSR B0329+54 was obtained after signal averaging (time folding) synchronized time intervals of approximately 0.865 seconds each for a total continuous observing time of 6 hours at 435.5 MHz using a bandwidth of 250 KHz.

TEMPO-derived Doppler corrections to the pulse sync frequency were made in real time every 10 seconds automatically via a GPIB connection to the sync frequency generator during the 6-hour observation time. Note that the peak intensities of the pulses from the pulsar are measured in hundredths of a dB relative to the signal-averaged noise floor.

An excellent result !!!

Confirmation of Results

There are two details which are note-worthy.

The first is that scaling roughly from the above display we can see that the time between pulses is approximately 714 ms - which closely matches the period ephemerid parameter from the ATNF database.

Note that the ATNF data is taken at an epoch in the past and so contemporary spin periods have to be corrected.

The second note-worthy point is that if an examination is made of the EPN Data Archive graphic on the right showing the pulse profile of B0329+54, two extra features are present.  The EPN profile shows a pre-pulse and post-pulse signal.  These two features are clearly visible in Joe's SDR14/SpectraVue result.

An overall result that is an excellent example of good science.

B0950+08

------------------------------------------------------------------
#     NAME          RAJ         DECJ                P0      S400
                    (hms)       (dms)              (s)     (mJy)
------------------------------------------------------------------
1     B0950+08      09:53:09.3  +07:55:35.7   0.253065    400.00
------------------------------------------------------------------

This pulsar is a more difficult target as it is about 6 dB weaker than B0329+54 at 400 MHz.

Joe's result for B0950+08 using SDR14 and SpectraVue are shown below.

This SDR-14/SpectraVue display of the pulse profile from PSR B0950+08 was obtained after signal averaging (time folding) synchronized time intervals of 0.400 seconds each for a total continuous observing time of 10 hours at 435.8 MHz using a bandwidth of 250 KHz.

Again, TEMPO-derived Doppler corrections to the pulse sync frequency were made in real time every 10 seconds automatically via a GPIB connection to the sync frequency generator during the 10-hour observation time. Note, again, that the peak intensities of the pulses from the pulsar are measured in hundredths of a dB relative to the signal-averaged noise floor.

Confirmation of Results

Scaling roughly from the above display we can see that the time between pulses is approximately 252 ms - which closely matches the period ephemerid parameter from the ATNF database for B0950+08.

Note again that the ATNF data is taken at an epoch in the past and so contemporary spin periods have to be corrected.

Another excellent result.

Joe's results show clearly what can be done by an amateur radio astronomer and, although his setup is most certainly 'un-amateur-ish' in quality, it nonetheless is an encouragement to others who are up for a challenge.