A photo/video account of comet NEOWISE by Gloucester Area Astronomy Club astrophotographer Jeremy Parker, and a review of some of the more recent Great Comets.
I just finished a little project to put some of my recent images to music in a slideshow video, most of which I showed at our recent GAAC astrophotography virtual meeting. This is my first attempt at such a video, but I think I will make them periodically, moving forward. I figured I would share it here, as you might find it entertaining or relaxing. Enjoy!
Galaxies comprise the largest self-gravitating systems of luminous matter in the universe, swirling masses of matter and energy just looking for trouble. Over the past few decades, astronomers have come to appreciate how fervently active galaxies can be. Besides hosting roiling clouds of intense starburst activity, they often also sport supermassive black holes in their centers that can pack a powerful punch. These myriad histrionics can affect the host galaxy's subsequent evolution and even the destinies of neighboring galaxies.
In Astrophysics for People in a Hurry, popular science author Neil DeGrasse Tyson summarizes the most frequently-asked questions about the universe and how we fit into the overall cosmos. Tyson is an American astrophysicist and science communicator who was born on October 5, 1958 in Manhattan, New York.
Sobel’s most recent novel The Glass Universe (2016) is split into three parts, “The Colors of Starlight,” “Oh, Be A Fine Girl, Kiss Me,” and “In the Depths Above.” Each part is further structured quite nicely into titled chapters that relate to the subject or person of interest. The book’s sweep is chronological, starting with Mary Anna Palmer Draper – the wife of astronomer Henry Draper.
According to recent popular science articles, there has been something of a revival of the traditional idea that our Milky Way is a 4-armed spiral galaxy, as opposed to having two spiral arms, as seen in the currently most popular rendition of our home Galaxy.
Each year, the American Astronomical Society (AAS) hosts two big meetings in January and June that span all of astronomy and its subfields of cosmology, helioastronomy, and planetary science. The COVID-19 pandemic took its toll, beginning in June 2020, when the meeting format pivoted to online presentations. The January 2022 meeting was canceled outright, but by June 2022, the society pivoted again, offering a hybrid mix of in-person and online formats. These two meetings underscored the unquenchable thirst for astronomical questing among our veteran and rising scientists. Here are a few highlights from these meetings.
The formula for collisional excitation of the atoms responsible for auroral emission can explain why green auroras from excited oxygen atoms can occur at relatively low altitudes, but red auroras from these same atoms are constrained to higher altitudes of lower density. The same formula also suggests much lower electron velocities (~100 km/s) than are required to excite the oxygen atoms to the required metastable levels for subsequent emission (~1000 km/s).
Fast Radio Bursts are flashes of radio emission lasting for several milliseconds. The time of arrival of signals depends on the radio frequency, called the dispersion measure (DM), which depends on the environment through which the signals travel, specifically the number of free electrons in their path. Very few FRBs have matches with sources observed at other wavelengths (Wikipedia - Fast Radio Burst).
Carl Sagan wrote that "If you wish to make an apple pie from scratch, you must first invent the universe.” We wish to know our home, so back we go, to the Big Bang, and step by step to today.
This edition combines fun and science as only Dr. Waller can do, as we take a colorful look at what's going on in supposedly empty space between the stars in the Milky Way galaxy.
