Aug 152016
 

NGC 6791 is an open star cluster in the constellation Lyra. Discovered in 1853, it is unusual in that there are three distinct populations of stars in the group. Along with a group of 8 billion year old normal stars there is a group of white dwarfs with a 6 billion year age and a group of white dwarfs with a 4 billion year age. This is contrary to the classic definition of open star clusters such that the stars of such a group are all born from the same molecular cloud and all have the same general age. Needless to say, this cluster has astronomers questioning their understanding of cluster formation and is heavily studied.
 
NGC 6791 was one of the few deep sky objects included in the field of view (FOV) of the Kepler spacecraft during its primary science mission.

(NGC 6791) [C: 56x60s]

(NGC 6791) [C: 56x60s]


Chart generated with Cartes du Ciel

Chart generated with Cartes du Ciel

 Posted by at 23:59
Jul 162016
 

(M 9; NGC 6333) [C:45x60s]

(M 9; NGC 6333) [C:45x60s]

Chart generated with Cartes du Ciel

Chart generated with Cartes du Ciel


Comet hunter, Charles Messier, discovered this object in June 1764. Now known as a globular cluster, this gravitationally bound group of stars is located in the constellation Ophiuchus. The dark area below and left of the cluster is part of dark nebula Barnard 64. The group is approximately 25,800 light years from the solar system.

 Posted by at 23:36
Jul 142016
 


The SkySentinel camera captured a bolide Monday morning just after 0200. Eight people reported the event on the American Meteor Society web site. Several reported it fragmented, but it must have done that after it hit my treeline.

 Posted by at 22:10
Jul 012016
 

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Yesterday, June 30th, was Asteroid Day. The following is quoted directly from the Asteroid Day website.

Asteroid Day is a global awareness campaign where people from around the world come together to learn about asteroids, the impact hazard they may pose, and what we can do to protect our planet, families, communities, and future generations from future asteroid impacts. Asteroid Day is held each year on the anniversary of the largest impact in recent history, the 1908 Tunguska event in Siberia.

The primary activity at the PTO is asteroid and comet orbit verification. The PTO’s primary telescope is too small to have any real chance of discovering a new asteroid or comet. But discovery is only part of the effort. The orbits of these objects can and have been changed by any number of physical processes. So, the PTO monitors known asteroids and comets to make sure they are where we think they are.

The way the PTO does this is to take a series of nine 300 second images of the target asteroid and then through computer analysis, determine sub arc second positions for the object. The information of at least three of the observations is then transmitted to the Minor Planet Center for comparison with predicted positions. The image below is a stack of 3 images with the asteroids circled showing their movement. The image is a negative of the stacked exposures. It is quite often easier to see darker objects against a white background than the other way around. Also visible is the track of a satellite recorded during one of the images.

[C:3x300s]

[C:3x300s]

The motion of all the asteroids is from the top of the image (East) toward the bottom (West). Since 2009 the PTO has submitted ≈2700 observations to the MPC.

 Posted by at 16:39
Jun 182016
 

Dwarf planets are always a subject of discussion during Planetarium Night at the Emerald Coast Science Center. It just so happens a couple of them are well placed right now and I was able to image Haumea and Makemake last week before they dipped below my western tree line. The Moon was close to full so there is some background gradient, but it is not too bothersome.

These dwarf planets also carry classifications of trans-Neptunian objects (TNO) and Kuiper belt objects (KBO). By convention, KBOs are named for mythological beings associated with creation and each was named accordingly. Each object is marked by two tick marks near the center of its image.

Haumea (136108) [C:9x300s]

Haumea (136108) [C:9x300s]


Chart generated with Cartes du Ciel

Chart generated with Cartes du Ciel

Haumea is named for the Hawaiian goddess of fertility and childbirth. It is currently in the constellation Bootes. Discovered in December 2004, it is approximately 770 miles in diameter and takes 283 years to orbit the Sun. Variations in the light curve of Haumea shows it is somewhat egg shaped and additional observations in 2005 found two moons orbiting Haumea.
 

Makemake (136472) [C:9x300s]

Makemake (136472) [C:9x300s]


Chart generated with Cartes du Ciel

Chart generated with Cartes du Ciel

Makemake is named for Easter Island’s Rapa Nui culture’s creator of humanity. It is currently in the constellation Coma Berenices and is 52.3 AU (4,860,659,162 mi.) from the Sun putting it just about as distant as it ever gets. This distance also makes it the furthest solar system object that I have ever imaged. Makemake is approximately 888 miles in diameter and takes 309 years to orbit the Sun. In April 2016, there was an announcement that the Hubble space telescope imaged a 100 mile wide moon orbiting Makemake.

 Posted by at 21:33