Category Archives: Uncategorized

Comet 38p/Stephan-Oterma

Comet 38P/Stephan-Oterma sporting a bit of a tail.  Imaged 16/12/2018

A Cosmic Christmas Present for 2018

This December Comet 46/P Wirtanen lights up the Christmas Sky.  Read about how you can get to enjoy the show as the comet passes Earth this December.  Read the Full Story Here


Comet 46/P Wirtanen Credit Martin Mobberley

Measuring the Redshift – Quasar 3C-273

Back in 2012 I achieved an ambition of measuring the distanct to one of the universes most distant and strange objects. Here’s the story of how that happened.

Quasar 3C-273 – Measuring the Redshift

Public Talk on August 14th

I will be giving a talk for Astronomy Ireland on August 14th.

“There’s nothing amateur about Science” by Dave Grennan, Raheny Observatory.

In this talk I will explore the many ways amateur astronomers can contribute to real practical science.  Some of the areas I will explore are

  • Minor Planet Research
  • Supernova hunting
  • Variable star monitoring
  • Spectroscopy

…and lots more

Venue is Physics Building Trinity College Dublin

Tickets are available from Astronomy Ireland

rahenyobservatory.ie is back!

Earlier in the year rahenyobservatory.ie was the victim of malicious hackers who set about taking control of this website.  The old website was so badly damaged it is not recoverable.  However I have been able to recover most of the old content and over the next weeks and months, I’ll be setting about reconstructing much of this.