Notes and Links from the March Meeting

Sky Notes

See Sky Notes in particular: Sunday 11th when the Moon and Saturn rise together, Monday 19th when the Moon, Venus and Mercury set together – suitably viewed from the Scout Scar mushroom and Helsington church grounds, Saturday 24th for the EAS public Moonwatch at the Brewery when the crater Plato will be casting shadows from the terminator division between lunar night and day and see late night 27th for Astronomical gamblers.

 

Astronomical News

See SpaceX landing video for the SpaceX landing.

Astrobites has been added to our links page joining Sky & Telescope and Astronomy Now

Guest speaker Dr Anne Sansom on Dust in Early-Type Galaxies

Dr Sansom discussed the presence of dust in early-type galaxies (lenticulars and ellipticals), and what that can tell us about how these galaxies formed and evolved. Dust is an indicator of what has happened in a galaxy over its life and can be added by galaxy mergers or stars as they age, and is destroyed over time, so how much dust is present can reveal much about what has happened to a galaxy over its life.

Much of the work comes from the Herschel-ATLAS survey, the Galaxy and Mass Assembly (GAMA) project for three specific areas of the sky, and the Herschel Virgo Cluster Survey (HeVICS). The results so far show that the early-types in the GAMA regions can broadly be split into dusty, with some star formation still underway, and non-dusty. The dusty ones are “green valley” galaxies, as opposed to the “red and dead” ones on the red sequence. In contrast, galaxies in the Virgo cluster have less dust in them, but the galaxies here are closely packed together so galaxy environment could be important in how dust is generated or destroyed in a galaxy. There is still a lot of work to do with this topic, but it is an active topic and more results are on their way.

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