Astrojohn

I am pleased I met with such a friendly and mutually supportive group of fellow patients: John, Kelly, Martin …… Helped on the dark days!

I have to say, all the staff in the linear accelerator team at QA hospital were great and kept our spirits up.

I will need to give the telescope a once over and clean. Then back to my stars!!

What a nice review from Olga Markova, 5 stars. I could not have expected more!

The lecture on technical challenges of measurement in astronomy went well and loads of interesting questions. All started from the slow (15years) of looking for exoplanets round V470 Cam. Easily visible reduction in the errors over the time I have been making measurements. Some of the error reduction techniques I have used.

Now loaded on arXiv.org Cornell University Archive.

1. arXiv:2206.06919  [pdf, ps, other]  astro-ph.SR astro-ph.EPEclipse timing variations in post-common envelope binaries: Are they a reliable indicator of circumbinary companions?
2. Authors: D. Pulley, I. D. Sharp, J. Mallett, S. von Harrach
3. Abstract: Post-common envelope binary systems evolve when matter is transferred from the primary star at a rate that cannot be accommodated by its secondary companion. A common envelope forms which is subsequently ejected resulting in a system with a binary period frequently between 2 and 3 hours. Where circumbinary companions are predicted, it remains unclear whether they form before or after the common en…
4.  ▽ MoreSubmitted 14 June, 2022; originally announced June 2022.Comments: 16 pages, 8 figures, 7 binary systems and 163 observations

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