One day, Two Astronomy Sessions

Monday, well actually Sunday, I decided that mornings were substantially better for trying to see anything in the “night” sky. Maybe that would be better said, when the sun in below the horizon enough to make it seem like it's night. That would be because Monday morning started about 5 AM with the idea from Sunday to get up early, hopefully before the clouds returned, and see what could be seen in the sky. With the haze, VERY high humidity, and the possibility that my eyes weren't completely open, the only real target was the moon. Fortunately, that's what I had planned for on Sunday.

The list of lunar objects is being drawn from the Astronomical League's “Lunar List”. These images are from the list and were close to the terminator (division between day and night), which is where I like to photograph them. As with my carvings, a low angle of light makes the relief stand out better.

Manilius and Rima Hyginus

This image shows off two of the targets, as will the next image, in one photo. The prominent crater just above the center is target #1, Manilius. The thumbnail sketch is that it's about 24 miles in diameter, has a central mountain, and is about 9400 feet deep. I find it's interesting that to the right of the crater, the terrain is rough, while to the left, the terrain is very smooth. I wonder why? Target #2 is at the lower left. It's a valley with a small crater more or less in the center of the valley. It looks somewhat like a bird in flight, with a small body and very long, thin wings. This is Rima Hyginus. “Rima” translates to “groove” and it's believed that this groove was once a lava tube that has collapsed. Its about 133 miles long and about 2 miles wide. The crater in the center is Hyginus, and is a sight of Transient Lunar Phenomena (TLP), according to Virtual Moon Atlas. The Phenomena? “smokes according to Sacco.” What?? Well, Hyginus is a crater believed to be formed by a volcano, rather than an impact crater. The moon, as I understand it, is supposed to be volcanically Inactive, but, who knows? Five minutes of research on the net does show some references to TLP activity in this area of the moon! Who knew? I might image this one more often.

This is another two in one image, this time two crater groups in the southern part of the moon. The craters, marked as you can see are Maurolycus and Gemma Frisius. Maurolycus is about 69 miles in diameter and that apparently is big enough to have small craters on the floor of this crater. For me, one of the interesting things to see is that the shadow covering the floor of the crater is larger than some of the surrounding craters. That most likely indicates how deep the crater is relative to some of the surrounding craters. Gemma Frisius is about 53 miles in diameter. Other than that, I don't know much more about these two craters.

Mars F10

Mars F 30

Yep, that's Saturn

The other two targets for the day are rather obvious when you look at them. They are, of course, Mars and Saturn. I might keep track of Mars as often as I can, because it looks like there might be a storm a-brewing. I want to see if the dark area that looks like a funny looking “X” changes over time. Of course, that means the clouds have to part, so good luck with that, I guess. The reason for two images of Mars that look slightly different, is because I wanted to experiment with changing focal length of the scope and observing it's impact on the resulting image. One result was expected, one not. The expected result: the F30 images looks a little darker. Why? (Thank you for asking.) The same amount of light is spread out over a larger field of view (FOV). Same light, larger surface area = dimmer image. The unexpected result: just how similar in detail the images are. I was expecting a little more detail in the F30 image, but it's not there. That very likely is because the seeing (steadiness mostly, in this case) was poor. Think of taking a picture of a runner. If the shutter is open too long, you get a blurred picture. Basically, that's what is happening here.

Until next time. 

Well, Here's an oddity

With all the cloudy weather, I decided to look at some other astronomer's blogs to see if I could glean some information on image processing. I think I hit the jackpot on Jerry Lodriguss's site Catching the Light. Specifically, this link http://www.astropix.com/HTML/J_DIGIT/VIGNET.HTM about uneven field illumination. Look back to an entry around April 10^th 2016 at the images and problems with the galaxy M100. Here's the problem image.

M100. Notice the light area extending into the corners.

As you can see, the field (or basically the image) is not evenly dark. There looks to be a bright bulls eye or circle near the edges. By using the ideas in Jerry's article, I was able to remove most, but not all, of the offending bright circle.

Same image as above, but with a lot of the brightness near the corners removed.

Now I think you can see that most of it is gone. I think that looks better, don't you? It shows a little less of the galaxy, but I think the general improvement is worth it. Nevertheless, I still think the best of the bunch is the one that's the luminescence channel only.

Still the best of the bunch. Black and white only image.

Oh, and the oddity? I wrote an entry without taking ANY images! Just recycled an old one.

Que the Apollo 13 music...

If you are as old as I am, you were around during the Apollo Moon Missions, which would be basically 1969 to about 1974 or so. I think. I can't remember exactly when the U.S gave up on going to the moon. A big mistake in my opinion. But that's not what this entry is about. The mission that was called the “successful failure” is, of course, Apollo 13. Intense to follow real time and a pretty good movie, staring Tom Hanks. That would be the music I'm referring to in my title. I think the original sound track is pretty good, too. I'm still off point, sorry. The point is that the landing area for Apollo was the crater Fra Mauro. It was not until Wednesday night, the 13^th, that I was able to image it, or anything for quite some time. The past several months have been the cloudiest I can seen for a long time.

I didn't know Fra Mauro's location on the moon until a few days before the 13^th. Earlier the spring, while it was cloudy, I decided I wanted images of the Astronomical League's Lunar List, which can be found on their web site. (You don't need a telescope for all the items, so you could download the list and see how many you could see.) I looked over the images of the moon I already have and found I already have about 60% of the list. One that I didn't, up until now, was Fra Mauro. And, to me, that's a rather important one. So, I basically got lucky on the evening of the 13^th because Fra Mauro was near the terminator, which is an ideal placement for imaging and it was CLEAR. Well, clear enough. So, without further ado (or finally...what's taking so long as some would say).....

So, which crater IS Fra Mauro? Well, it's this one. With the white dot that is

Now that you know which one it is, this is the same image without the identification.

Thanks to Virtual Moon Atlas, this is where Fra Mauro is in relation to the whole moon.

My image is the best 95% of 1100 images taken on the 13^th. Remember that I do lunar and planetary imaging with a webcam, so that represents only 34 seconds of time to take the 1100 images. In fact, I was able to open the observatory, turn everything on, get everything aligned, take the images, visually observe Alberio (probably my favorite double star) and epsilon Lyre (the famous “double double”. Naked eye, it appears as one star; in binoculars or telescope at low power, it appears as a double star; on high power, the each star of the double star resolves into a double star; hence the double double. If a planet could fit somewhere in there, it could have 4 suns. Probably wouldn't get much sleep....). Then turn everything off, put everything up, and close the observatory, all within an hour. That's pretty fast for me.

Well, that's about it for this time. Should the skies part again for an hour or so, I hope to get another Mars and Saturn.... I've got an idea for something a little different I want to try next time.

PS, Just as an aside, my image happens to show one of the many challenges of imaging, dynamic range. Dynamic range here refers to the difference, in the image, between the lightest and darkest areas. The crater in the upper right of the image is completely white while the left side of the image is completely black.  Computers assign a value of of 0 (zero) to black and 255 to white on most displays (which are 8 bit). When the limits of 0 or 255 are reached, in the image, information is lost. There is no way to discover if there is more information, or image, in either the black or white regions. The "trick" in most imaging is to not reach either limit, 0 or 255, in an image. Sometimes, it just isn't your day... :)