27 April 2017

On April 19, the asteroid known as 2014JO25 made a newsworthy flyby of the earth. Although it passed by at 4.6 lunar distances and was never really a threat, it caught the attention of astronomers. This video was made a few hours before its closest approach to the earth.

26 April 2017

In February, I posted video featuring some of the small, faint galaxies around the Milky Way that are collectively known as the “Local Group”. In the two videos below, we’re extending our exploration of galaxies beyond the Local Group of galaxies to the largest nearby galaxy cluster called the Virgo cluster. These videos (and especially the map) might be best viewed full screen.

16 March 2017

Earlier this year I posted a video of the asteroid Hermione momentarily occulting (blocking) the light from a star. This week, on 14 March, I captured a video of a similar event. This time, the asteroid Protogeneia blocked the starlight of a star for 37 seconds. The following video describes and shows the event.

27 February 2017

Earlier this year I posted a video tour of the Andromeda Galaxy. Andromeda and our own Milky Way galaxies are the two largest members of what is known as the Local Group. The Local Group is comprised of about 50 galaxies (most of them faint and diffuse dwarf elliptical, spherical or irregular galaxies) distributed though a radius of about 5 million light years from the Milky Way.

But our galactic neighborhood, the Local Group, is just the tip of a galactic iceberg known as the Virgo Supercluster. In the spring, the constellation Virgo comes into prime viewing position and many of the galaxies that belong to the Virgo Supercluster will be coming into better view then. I hope to be touring some of these later this spring. So I thought it might be useful to show you around the Local Group and get you oriented to our local galactic neighborhood with the closest galaxies before looking further into the Virgo supercluster. (Best viewed at full screen)

19 February 2017

Comet 45/P (aka”Honda-Mrkos-Pajdusakova” after the three co-discoverers) comes around every 5.25 years. I missed it when it was “inbound” but captured it last week “outbound” on it’s way past the earth. I had hoped it would be brighter but it’s been fading rapidly as it moves away from the sun and past earth.

Here are two video clips that I prepared from frame captures from the video camera on the telescope.

22 Jan 2017

With the Andromeda Galaxy being a prominent feature of the late fall, early winter sky, I decided to feature it in an Astrovideo. But, for a variety of reasons, I didn’t get around to capturing any images until late December, early January. I’ve put together the following video clip that describes some of the facts and features surrounding our closest galactic neighbor. The Milky Way and Andromeda galaxies are the two largest members of what is known as the Local Group of galaxies. This group of about 50-60 galaxies inhabits a region that is about 10 million light years diameter. The Andromeda and Milky Way galaxies appear to be on a collision course that is expected to occur in about 4 billion years.

Tour of the Andromeda Galaxy

6 February 2017

Asteroid Occultation

Several years ago I became interested in a niche of amateur astronomy called “occultation timing”.

When an asteroid passes between a star and the earth, the starlight is momentarily blocked (“occulted” is the technical term). In the 21st century, our knowledge of the positions of stars and the orbits of the asteroids is sufficiently advanced that these events can be predicted. The time and location of the path of the “asteroid shadow” as it passes over the earth can be predicted with remarkable, albeit still imperfect, reliability. If an event can be observed, and the time interval that the starlight is blocked (occulted) can be measured, then, knowing the orbital velocity, the width of the asteroid can be determined.

I am among a group of amateur astronomers who observe and measure these events. And although the prediction capability is fairly sophisticated, there is still enough uncertainty in the knowledge of star positions and asteroid orbits that many of the events that are predicted to happen at my location turn out to be misses. Last week, however, I observed a “hit” on an asteroid named Hermione. I recorded the event and produced a short video clip on this topic. This video is best viewed at “full screen” mode to see the disappearance and reappearance of the star as the asteroid passes.