A Historic Day

By: Tim Nelson, Hampshire Astronomical Group

History was made on 14 September 2020 when Phosphine gas (indicating the possibility of life) was found in the atmosphere of Venus and the HOYS Citizens Science Project had its 30,000th image uploaded and processed into its database.

The image was of IC5146 (the Cocoon Nebula) with many stars of interest and was taken by me in the Blue filter.  My group is based at Clanfield Observatory in Hampshire but owing to the Covid pandemic has been closed except for a few hardy observers. Thus, the image was taken from the Horndean Observatory (my back garden).  The Group has several members who contribute to the HOYS project and between us we have uploaded the third most images to the project to date.

To try and get as many images as possible I use my own single shot colour cameras (SSCC) a Canon EOS 600D (Mod) DSLR and an Altair 183C Cooled camera.  At the Observatory, I mainly use the Altair camera with a 12 inch Newtonian telescope. Owing to Covid, I have been using my own Skywatcher EQ5 Pro mount with a Skywatcher 127mm Skymax telescope with my DSLR.  It was with this rig that the 30,000th image was taken.

My Garden is a Class 4 Bortle site despite being in the middle of a housing estate.  Because of my location I use the mount unguided and I take short 60s exposures to avoid the light pollution and to keep image losses to a minimum.  I had taken 20 subs but lost one to an aircraft trail giving a total exposure of 1140s on the evening of September 12th. Settings were for a Focal Length of 1526mm, @ ISO 1600.  The images were pre-processed with 30 Bias, 30 Dark and 20 Flat calibration frames in PixInsight.

Once done the individual Red, Green and Blue channels were extracted and uploaded to the database on September 14th.  I was pleased and honoured to have been informed by Dirk that I had uploaded the 30,000th image.  The historic image was the Blue channel and was my 1,353rd image uploaded to the site since starting with the project in 2018.  I hope to continue contributing to the project for as long as possible and keep adding to the database.  I also enjoy seeing the regularly published analysis graphs showing the brightening and dimming of the target stars and hope to become more involved in my own analysis in due course.

I have always been interested in Astronomy and the stars, but became familiar with named bright stars in both the northern and southern hemispheres, which were used for pre GPS Astro Navigation in a previous incarnation as a Royal Naval Officer.

I joined the HAG in December 2001 and became interested in Astro photography.  After some tuition, which stood me in good stead for the HOYS project, I am now the imaging representative on the group’s committee.  After several years of imaging I was looking for something else from Astronomy and in 2018 our Chairman put out a challenge for the group to become more involved with doing “actual science”.  The Group has already assisted students from Portsmouth University in the Cosmology and Maths departments with PhD projects looking at binary star systems and exo-planets, but this seemed very involved for an ex simple sailor.  I went on line and found reference to the then HOYS-CAPS Citizen Science Project run by Dr Dirk Froebrich from the University of Kent.

After a few teething problems, soon resolved by Dirk, several HAG members took up the challenge of providing images for the HOYS project.  To date we have uploaded over 1,800 images.   The Observatory has several telescopes which can be used for the imaging and also has 2 CCD cameras with filter wheels.  These items are usually in great demand and are very popular with other group members so the use of own equipment helps maintain a steady flow of uploaded images.

I really enjoy taking the images and try to take as many targets as possible each night.  Using the SSCC and taking 20 x 1 minute subs each target has up to 20 minutes exposure often reduced by aircraft, satellite trails Security Lights and cloud.  I have found this gives me the opportunity to take up to 8 targets a night and also to get some sleep. However all images are of great value to the project.  Processing is done by PixInsight the following day, and uploaded to the Database.  Once there Dirk and his team of PhD students look at the data and investigate the brightening and dimming of any target stars of interest.

Earlier this year I was also privileged to be a co-contributor (having uploaded several images) and co-author to the published paper on:

“A survey for variable young stars with small telescopes: II – mapping a protoplanetary disc with stable structures at 0.15 au”

I think this meets the Chairman’s challenge to be involved with real science.