Saturday, March 11, 2017
SOLAR DISK AND GRANULES Taken by Alfred Tan on March 11, 2017 @ Singapore
This morning I started with 3-band full-disk solar imaging at H-Alpa, Calcium-K and White Light wavelengths. The Sun was spotless with little details on the disk. Switching over to G-band imaging changed the observing experience. Remarkable details of granulations showed the effects of plasma heating the solar surface through convection currents within the Suns convective zone. It is amazing to see the granules which have diameters in the order of 1,500 kilometer (roughly the size of the state of Texas). For the G-Band imaging session, I used a full aperture Energy Reduction Filter (ERF) mounted on the front of a Celestron NexStar 8-inch SCT. At the rear, a x5 Televue barlow was connected to a 2 diagonal. An ASI 174 mono camera had an Edmund Optics 25mm 430/10nm G-band filter fitted into its nose tube at the other end of the barlow.