About Astrojohn

I am a science geek! Interests Astronomy, Skiing, Philosophy, basically any form of technology including writing automation software for my observatory. I will also share this with others using the same EQMOD/Astroart tool set.

Starlink is a pain!!

I have missed another night of binary star measurement due to interference from Starlink.

Comet c/2020 F3

Saw the comet last night and this is what it looks like with normal 3sec exposure over Selsey..

Comet C/2020 F3 – Neowise

Starlink costs researchers time and money!!

So much space pollution being caused deliberately by Elon Musk. My research could become more difficult as it will for anyone wanting to look beyond the earth. Over 11000 satellites to be launched…your joking, We only have a small percentage so far..

It wrecked my measurement of distant binary systems last night..


M51 very short exposure clear night

This is one of my favourite galaxies. Just did a quick exposure after doing some adjustments on my telescope.

M51 240seconds.

Take a look at all the space junk astronomers have to avoid!

This is a real time interactive display of most of the recorded junk and satellites!


Move around it with your mouse!

Binary System HS0705+6700 Plot

Nice plot of the light curve for HS0705+6700, 2.3hr, post-common envelope eclipsing binary system. Spectroscopy and light curve analysis indicated that the secondary companion was a low mass red dwarf star with mass and radius of 0.13M0 and 0.19R0

Cloud sensor -Pi build

Just completed the design of a cloud sensor to replace the one that died.

The system has a telnet server built into the Pi. This allows remote systems to access the sensors and display the IR sky temperature, barometric pressure and humidity. The IR sensor is quite accurate and has internal calibration.

As you can see the IR sensor is being tested measuring the heatsink temperature of the Pi.

I have also built remote displays to communicate with the sensor system.

Remote display
IR and Humidity/Barometric sensors.

DE Cvn Binary System- Data Needed

Hi everyone. I need time series data on this system. To include mid minima timing in BJD format. I am starting a research project on this star.

Email me if you have any early pre 2009 data.



Source of reference stars where you can check for suitability as reference.

Link to the online version..


Paper on objects round eclipsing binary stars.

The paper is now on the archive of scientific papers:


Quite a significant amount of new data from our group. Some interesting departures from early expectations. It will clearly take some ongoing research to identify the mechanisms that are producing some of the effects.

Seems to be getting some interest!