Dec 262017

This comet was discovered by Ari Heinze of the University of Hawai’i using their ATLAS system. He came across the 18th magnitude object on the 2nd of October.

The 12 frames that make up the animation were taken the evening of the 25th of December. Each frame is a 300 second exposure for a total of 1 hour of movement. Just visible is a hint of a curve in the tail. As is usual for my images, north is to the right and east is towards the top.

C/2017 T1 (Heinze) is quickly traversing the constellation Cancer. It is currently between the orbits of the Earth and Mars and is passing up through the plane of the solar system. It will pass closest to the Sun (perihelion) on Feb. 21st but come closest to the Earth on the 4th of January.

The PTO’s tree obstructed view of the sky.
Chart generated by TheSkyX.

Calculations for the comet’s brightness predict it will be brightest viewed from the Earth on the 6th of January. If it gets as bright as predicted (Mag. 8.8) it will be visible in moderately sized binoculars or small telescopes. However, a comet’s response to the Sun’s energy is very unpredictable and thus brightness predictions are very unreliable.

 Posted by at 15:23
Dec 212017

The Horsehead Nebula (Barnard 33) [L:79x60s;TR:26x60s;TG:24x60s;TB:25x60s]

There are 3 basic types of nebulae. This image of an area near Orion’s belt features all three. At lower left, the blue nebula (NGC 2023) is a reflection nebula. Lit by star HD 37903, the gas and dust simply reflect the star’s light. The red background nebula (IC 434) is an emission nebula. Located about 1,500 Ly from the Sun it receives enough energy from Sigma Orionis that the hydrogen in the cloud glows like a neon sign. The Horsehead nebula (Barnard 33) is a dark nebula. This cloud of gas is dense enough to completely block the light from IC 434. The spray of blue light from the left is scattered light from Alnitak, the eastern most star in the belt of Orion.

First discovered by Williamina Fleming on a photographic plate in 1888, the dark cloud remains a very difficult visual object to view in a telescope. It takes a very dark clear sky and a fairly large telescope to just make out the outline of the horse’s head.

 Posted by at 14:29
Nov 202017

For a number of years now the PTO has sponsored a youth soccer team. This year I was invited to one of the games and my schedule finally allowed me to attend (on the second try). So, here they are, the 2017 Pear Tree Observatory U8 boys soccer team after their quarter final match.

I would like to thank Coach Blake for the invite and the team for the much appreciated plaque. We are looking forward to the 2018 season.

 Posted by at 13:53
Nov 052017

Although the bottom portion of this image is largely Mare Imbrium (The Sea of Rains) what I was concentrating on was catching sunrise in the large circular area towards the top and just right of center. This area is Sinus Iridum (The Bay of Rainbows). The ‘bay’ is a 236 km (146 mi.) crater that predated the impact that formed Mare Imbrium. The crater was flooded by basaltic lava that resulted from the much larger Imbrium impact.

There are very few named craters in the bay, but several surface ridges called dorsa are visible. A dorsum is a ridge formed when the lava cools and contracts.

To put the size of the ‘bay’ into perspective, this is a 146 mi. wide circle centered on Niceville, FL.

Sinus Iridum, along with most large features of the Moon, were named by Giovanni Battista Riccioli (1598-1671). Riccioli was an Italian Jesuit priest who included the names as well as detailed maps of the Moon in his seminal work, Almagestum Novum (New Almagest). Published in 1651 and consisting of 1500 pages, the work was used as an astronomical reference for many decades. His names and naming conventions are still used today.

 Posted by at 13:40
Sep 222017

As many of you know the OSIRIS-REx spacecraft made an Earth gravitational assist fly-by today. The spacecraft needed the slingshot maneuver to make it to its rendezvous with the asteroid Bennu in August 2018. The spacecraft will orbit the asteroid for up close study, then drop low enough to grab a sample of the surface for return to the Earth in September 2023.

NASA put out a call to amateur astronomers to take images of the spacecraft as it approached the Earth. So, for the past week I have been attempting to do just that. Last night the spacecraft was finally bright enough for me to catch it in a series of exposures. Even so, the speed, brightness and size of the spacecraft makes it very difficult to see.

The above image is the third of eight 300 second exposures that I was able to get before the clouds closed in. The circle shows the location of the automobile sized craft which should give you an idea where it will be in the following animation. The craft’s motion is from upper right to middle left.

I had to stretch the images as well as invert them to make the faint streak a little more visible. This close to the Earth the apparent velocity of OSIRIS-REx is obvious.

[Update: 03 Jan 2018] OSIRIS-Rex is now projected to arrive at Bennu in December of 2018. Approach operations will begin in August.

 Posted by at 14:37