Lagoon Nebula and friends (14 Jun 2020)

 DSO, Globular Cluster, Nebulae, Open Cluster  No Responses »
Jun 162020
 

I am still developing the procedures necessary to process one shot color (OSC) camera images. This is the first D90 image I have processed using the color information. The steps to process an OSC camera are totally different than the steps I use to produce color images taken by my science camera. The larger FOV also adds additional complexity. This image is 2.83° wide versus my science camera having an FOV of only 24′ (arc minutes). However, the increased area makes it much easier to image multiple objects without having to assemble a mosaic of smaller images.

This picture is centered on an object in the southern constellation Sagittarius: The Lagoon Nebula. Also known as M 8, it is a large emission nebula being energized by the open star cluster NGC 6530 that lies in it. Also easily visible towards the lower right is M 20 (The Trifid Nebula) containing both emission and reflection nebulae. The small concentration of stars at the upper left is the globular cluster NGC 6544.

Lagoon Nebula (M8) [F:10x120s]


Chart generated by Cartes du Ciel (CdC)

Chart courtesy of IAU/Sky&Telescope

The vertical yellow line that runs all the way through the CdC chart is the ecliptic. Since most asteroids orbit in the plane of the solar system, the image contains a lot of them. I counted 31 identified on the chart by small green dots, but due to the image scale and the asteroid’s magnitudes I couldn’t find any of them.

Both M 8 and M 20 are just visible with binoculars. Using the constellation chart, observe just above the spout of Sagittarius’ Tea Pot asterism (heavy green lines).

 Posted by at 18:45

The Great Orion Nebula (M 42)

 DSO, Nebulae  No Responses »
Jan 012020
 

With the PTO’s science camera still in the shop, I drug out my 15 year old Nikon D50. Although it doesn’t have the dynamic range or resolution of the science camera it sure is easier to create a full color image.

The Orion nebula is one of the nearest star forming regions to the Sun and based on recent analysis, is home to 700+ stars in various stages of formation. The mighty Hubble space telescope has also recorded more than 150 infant solar systems in the stellar nursery. Technically, the young systems are known as protoplanetary disks AKA proplyds.

Orion Nebula (M 42) [F:15x30s]

The nebula is just at the limit of naked eye visibility. It is the middle object in the ‘sword’ that hangs from the hunter’s three star belt.

 Posted by at 21:37

NGC 2149 and friend

 DSO, General Commentary, Nebulae, Spacecraft  2 Responses »
Jan 312018
 

The target of this image is NGC 2149, a small reflection nebula in the constellation Monoceros (the Unicorn). It is quite near the constellation Orion and often gets overlooked due to the more flamboyant objects in “The Hunter”. I routinely exclude images taken of deep sky objects when a satellite intrudes into the photo. The brightness of the intruder skews the desired object’s post processing. I must admit however, last night I intentionally chose NGC 2149 because of the impending satellite pass. The guilty party this time was the Hubble Space Telescope.
 

I decided to attempt the exposure knowing full well the Moon’s brightness would cause a strong gradient in the exposures. After all, the Moon was only a few hours from entering the Earth’s shadow and the resultant total lunar eclipse. Hubble would cross my FOV in just over one second. It takes 10 seconds to download an image from my camera, so in order to not miss the pass I set the exposure to 300 seconds and started it a couple of minutes before the expected arrival. I then joined family members in the front yard to watch the flyby. Hubble silently glided west to east and near the point where it disappeared, it did its best imitation of an Iridium flare. The scope’s solar arrays were at just the right angle to reflect the Sun’s light right back at us. It then faded as its orbit took it into the Earth’s shadow.

Luckily, the satellite’s orbital elements used to predict its path were right on and the 300 second exposure showed the very bright telescope streaking through the image. I then took additional images of the nebula to increase its brightness a little. The result is a stack of one 300 second image and 25 sixty second images.

 Posted by at 15:17

The Horsehead Nebula (Barnard 33)

 DSO, Nebulae  No Responses »
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

Heart of the Heart (IC 1805)

 DSO, Nebulae  No Responses »
Nov 182016
 

Once again the diminutive FOV of my system does not lend itself to extended objects. Thus, it does not do the Heart Nebula justice. In fact this image only shows the central part of the heart shaped portion of IC 1805. However, it does show the small very young cluster of stars (Melotte 15) that ‘lights up’ the nebula. Several of the stars have estimated masses in excess of 50 times that of the Sun and it is those stars whose extreme output provides the energy to excite the surrounding hydrogen cloud into emitting the familiar red light. The energy is also what is sculpting the surrounding cloud into the fanciful shapes visible in the image.

The Heart Nebula (IC 1805 detail) [Ha:67x120s ]

The Heart Nebula (IC 1805 detail) [Ha:67x120s ]


This image is taken through a Hydrogen-Alpha filter that limits the light passing through to that with a wavelength of 656.28 nm. In addition to distinctly showing where the energized hydrogen is located, it also is one way to limit the effect of a nearly full Moon and common light pollution. This image was taken on a full Moon night.
 
Chart generated with Cartes du Ciel

Chart generated with Cartes du Ciel

 Posted by at 14:48
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