2021

Northeast Astronomy Forum and Space Expo - online and free April 10/2021

Normally requiring a trip to the USA, the 2021 NEAF expo is being offered virtually this year. See the image below for a summary of the event. Additional details can be found at NEAF Expo.


New nova discovered in Cassiopeia - March 20/2021

On March 18, a nova (Latin for new) was discovered by Yuji Nakamura of Japan in the constellation Cassiopeia; this nova is known as Nova Cas 2021. Initially its magnitude was about 9.6, and as of March 19 it had brightened to magnitude 7.5. Once discovered, astronomers from the National Astronomical Observatory of Japan started to analyze the nova and determined it is of the classical variety.

Classical novae are thought to be created in a close binary star system consisting of a white dwarf and a main companion star. When the orbital period falls in the range of several days to one day, the white dwarf is close enough to its companion star to start drawing accreted matter onto the surface of the white dwarf, creating a dense but shallow atmosphere. This atmosphere, mostly consisting of hydrogen, is thermally heated by the hot white dwarf and eventually reaches a critical temperature causing ignition of rapid runaway fusion. The sudden increase in energy expels the atmosphere into interstellar space creating the envelope seen as visible light during the nova event and in past centuries was mistaken as a new star.

Novae are unpredictable in terms of how long they will be visible, so try to get out with a pair of binoculars or a lower power telescope to see this one while you still can; the following picture from Astronomy Now shows where you can find it.

For more reading see this link.


March Messier marathon - March 17/2021

March is a great month to hunt for Messier objects. It is common to challenge oneself with a Messier marathon on any moon-free night in March. From our mid-northern latitude, it is the only time when it is possible to view all 110 Messier objects in a single night; another option is to split it up into a few nights. You will need a dark location with few obstructions on the horizon. The idea is to start with the brightest objects in order to gauge visibility in the darkening sky (items 1-11). M77 and M74 are very challenging dusk objects. You will need to work from west to east, since objects setting in the west will disappear/set first. Over the course of the night, new stars will rise. By early morning you can attempt to view the final objects on the list. Dusk and dawn objects are the most challenging ones since the sky is not truly dark. Included here is a list that was designed specifically for our club. Binoculars are great for many of the objects, while others are only visible with a telescope. Enjoy the challenge!!


Lunar X and V visible on the moon - March 14/2021

Two visual phenomena will begin to be visible on the moon on March 20 at about 18:03 EDT (in Kincardine). These are the lunar X and V, two Clair-Obscur visuals that are created due to the interplay of light and shadow on the moon. These shapes are visible generally a few hours before the first quarter moon which hits us on March 21. There is an oppportunity to see these every month depending on Earth's location using a low power telescope or set of binoculars. The X is caused by light illuminating the rims of three craters, Blanchinus, La Caille and Purbach, and can be seen slightly below the lunar terminator; the V is caused the light illuminating the crater Ukert along with several lesser craters. The following image from Optics Central shows what to look at on the moon.

This article by David Chapman gives more details on the lunar X phenomena for those interested. Some future dates where the lunar X may be visible in our area as calculated using the Lunar Terminator Visualization Tool (LTVT) are April 19 07:09 EDT, May 18 19:35 EDT, June 17 07:27 EDT. Note that these dates roughly correspond to that of a first quarter moon. One could also expect the lunar X and V to be visible several hours after a last quarter moon.

Also on this day is the spring equinox (in the northern hemisphere at least). In its apparent motion on the equinox, the sun crosses Earth's horizon directly at the east when the sun rises and at the west when it sets; there is an approximately equal amount of day time and darkness. This day also marks the first official day of spring.


New moon - March 14/2021

In her most recent minutes, Lorraine challenged us all to find the new crescent moon on March 14/2021. The opportunity was small with the sun setting at 19:30 and the mooon setting at 20:50 and especially with the extreme wind of the day. I went down to the beach in Kincardine and managed to capture this snapshot with my phone of the moon about a half hour before it set.


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