Many years ago our youngest daughter used the International Star Registry to name a star for me. I received a nice certificate and a map showing where the star was located. Its coordinates were given as well as the magnitude. I never could find it with the equipment I owned. Based on the coordinates given in the certificate, it is indicated by the yellow markers somewhere in Pisces in this image from the screen of my desktop software.
In order to give a sense of perspective about where this star is located, I zoomed out from that spot while recording a video of the screen. As the view widens, the Pleiades and then Orion appear at the left. Note the movements of the mouse pointer.
My next step to locate the star with a telescope. I will try with the U of Iowa Gemini telescope in Arizona. It should be able to see it with a long enough exposure.
I recently read a post by fellow blogger The Belmont Rooster about the scientific naming of plants. In his post, he described with examples how the names are determined according to some rules and criteria. The system brings the many plants of the world into a naming hierarchy with allowances for special cases and situations. If you like plants, check out his blog.
Knowing that I am an amateur astronomer, he asked if the stars also have a naming system. I said they do. It seemed a topic worthy of some discussion. Come along with me. To set the stage, we will start with some music. Thank you, Willie.
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During 2017, the inner solar system has been joined by several comets. Most are not bright enough for the casual observer to see. Those with dark skies and large enough telescopes have enjoyed one of these visitors, comet C/2015 V2 (Johnson). The discovery was by Jess Johnson in late November of 2015.
Comet naming is systematic. The letter C means it is a one time visitor. A letter P would be used if the comet returned periodically such as Halley. Discoveries are denoted by the half-month in which they occur. The first comet found in the first half of January would have A1 at the end of the label. If another was found in the first half of January it would be A2, etc. The fourth one found in the second half of February would be labeled with D4. The V2 for Comet Johnson means it was the second comet discovered in the second half of November. The eleventh month means the 21st and 22nd letters of the alphabet (U and V) are used for those half-months.
One of the better images of C/2015 V2 is from Tenagra Observatories in Arizona. Details of their observation is at this link. Click to embiggen.
I was curious what the orbit looked like. I found a web site by Dominic Ford called In-The-Sky. His simulation showed the orbits of the inner planets and the comet which could be rotated and viewed from different perspectives. Here is a short screen video capture from his site. The video shows the comet on 30 May 2017.
I requested an image of Comet Johnson from the University of Iowa Gemini robotic telescope in Sonoita, Arizona. It was taken at 12:42 am CDT the morning of 30 May. The 60 sec exposure in visible light showed the halo and faint tail. Click to embiggen.
Sunrise today was 7:23 am. At 6:49 am, the Moon was barely above the eastern horizon, presenting a narrow sliver of reflected light. Earthshine lit the rest of the Moon faintly.
A wider view showed the star Porrima, goddess of prophecy, watching the proceedings nearby.
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Bright Venus and Mars in center at 6:45 am today. They are joined by Sigma Leo at top and Tau Leo lower right.
Simulation of the passing of Mars by Venus between 2 October and 8 October.
Two days earlier I posted some photos of Venus and Mars in the pre-dawn light. The positions of Venus and Mars were getting closer each morning. October 5th was to be the day they would be closest at 1/4˚ apart. For comparison, the Moon’s diameter is only 1/2˚ wide.
Our weather forecast said it would be raining on the morning of the 5th. I assumed that previous post was going to be all I would get to share about their conjunction. Today I looked outside before 6 am and was thrilled to see a clear sky. I got the camera and tripod to capture the unexpected scene.
First is a screen capture from my planetarium software showing the planets on the 3rd and the 5th of October.
Next is my photograph of Venus and Mars at 6 am on the 3rd of October. It is adjusted to be the same scale as the first image.
Finally, my photograph of the two at 6 am on the 5th of October. It is adjusted to be the same scale as the first image. They were about half the width of a full moon apart. Mars was hard to see without the aid of binoculars. By 6:30 am, the sky was too bright to see Mars. Venus remained bright and easily seen. In fact, in clear skies, Venus is not hard to see in the daytime if you know where to look.
Venus has been gracing the morning pre-dawn sky for several weeks. It raced past Earth in its orbit around the Sun and is receding from us quickly. It will pass behind the Sun early in 2018 before emerging as an evening apparition.
Mars is positioned farther away from us than Venus and nearly along the same line of sight. On 5 October, early morning risers can see the two nearest to each other. Look at about 6 am low in the eastern sky on a clear morning. Binoculars will help spot dim Mars. It appears we will suffer from cloudy skies here in the midwest.
This morning I was up early and looked for Venus. It was hidden by low clouds to the east. I waited and was able to see both Venus and Mars emerge from the clouds. Notice the faint outline of a tree on the right side of the image. All images have been slightly modified to make them more easily viewed. They look best enlarged on a monitor screen. You might not see anything on a phone or tablet.
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