Physics Photo of the Week

Physics Photo of the Week January 30, 2023 Update on Comet C/2022 E3 (ZTF) Photos by Donald Collins                   The comet featured on Jan 20 PPOW has become brighter.  The photo above was taken on January 27, 2023 using a DSLR color camera mounted on a tripod.  The dusty tail appears greenish due to the sunlight scattering off the small dust particles that are blown away from the comet. The comet was still not visible to the naked eye, but a time exposure with a normal lens on a DSLR camera barely shows the comet.  The image on the right shows a wide-angle photo of the Big Dipper on the right side of the photo.  The pointer stars point to Polaris, the North Star.   The comet last Friday was in the location of the circle, but barely visible in the photo. The original wide-angle image above was zoomed in by cropping with the computer and shown at left.  This clearly shows the comet that resembles a fuzzy star in the center.  This is similar to a view with binoculars, but the b

  Comet C/2022 E3 ZTF Photo by Donald Collins, College View Observatory For almost a year astronomers have been anticipating the arrival of a "major" comet in January and February of 2023.  The discovery of this comet was made by the Zwicky Transient Facility (ZTF) in March 2022. (Bob King, Sky and Telescope, January 2023)  Observations of position over the course of several weeks have enabled astronomers to calculate the precise parameters for the orbit (inclination, period, eccentricity, etc).   Anyone can download the parameters and load into a sky-viewing and telescope guiding program to direct a telescope to point to it. I made this photo the night of January 12, 2023 with the College View Observatory 14 inch telescope and CCD camera.  This photo consisted of stacking about 10 digital images of 60 seconds each.  Compared with the stars, the comet is quite bright, but we can see stars through the dusty tail.  The illumination of the comet is reflected light from the Sun.