Pascal Hilkens Astro Page

Saturday, June 3, 2017

Ligo detects gravitational waves for the third time.

For the third time, LIGO spots gravitational waves? This time the merging black holes are as far as 4 billion ly (farrest so far) from earth and a combined 49 sunmasse s - see article.

Update geschiedenis van astronomievereeniging Helios

De geschiedenis van astronomievereeniging Helios te Averbode werd geactualiseerd. Zie hiervoor link naar de blogpagina.

Start of NLC season

June and July are typically the start of NLC or Noctilucent Clouds. Those highest clouds we know are showing up around 80km above Earth's surface. They are very cold and exist of very small ice crystals. When sunlight hit those crystals they will show up as a blue glow. They appear during the summer months and the best way to observe is about 2à3h after sunset or 2à3h before sunrise.

The picture below I took last last year mid July, 1h before sunrise.

How to calculate exposure time during suneclips

When making pictures of the sun and during a totality it's important to have the right settings. You can experiment yourself upfront with the sun high in the sky and using your solarfilter. Try out shutter speeds from 1/8000s -1s for different ISO numbers and f/stop numbers and see what's the best result. As long as the sun is visible this setting can be used. During totality settings need to be adjusted and without filter.

For more information see this calculator or see below chart for settings during totality and what detail (chromosphere, corona,..) you want to photograph

Weather Summary May 2017

As a summary May 2017 was a warm and dry month.
Average temperatures are up to 2°C higher then last three years. In comparison with last 4 years, May 2017 was a very dry month with 23 dry days and only 45 liter/m2.