A Constellation Preview (Blog #2)

Looking at the images I posted from my last blog, I can see where I need to find better ways of making images, so I have worked on that. I have also been working on a way to plot the constellations that does not involve copyrighted material. I think that I have succeeded in this using the data from the HIPPARCOS satellite, Microsoft Excel, Microsoft Paint, and coconut shells. As an example of the result, here is an image from the next post, the first post on the constellations, a map of Ursa Major (including the Big Dipper) with named stars.



Now if I can only find a way to make the image display with the detail that I want it to show ...

The Planets Right Now (Actually Saturn, Saturn, and More Saturn) (Blog #1)

PREFACE: I’m going to rely more strongly on sketches I make at the telescope than on photographs, because photos can be a lot cooler than what you can see with eye – the photo can be taken over a long period of time, and reveal colors and structures that we can’t see by eye. This is actually one of the complaints that I have about a number of observing aides; by showing photos with more details than the eye can see, a visual observer could be greatly discouraged instead of being able to learn to see what is there. Happily, planets do not have that problem. Planets are so comparatively bright that sensitivity is not a problem, and in fact the eye does a better job than most non-spacecraft cameras for seeing details on the planets. Plus, there are some really cool planetary images in the public domain.

The primary purpose of my blog over the first year will be discuss each constellation visible from the continental United States in turn, with special emphasis to the Messier Catalog, Charles Messier’s list of 110 galaxies, clusters, nebulae, and … stuff. (I’ll explain that in my first constellation post on Ursa Major – the Big Dipper and more). I’m not just going to be doing that, because I want this to be interesting for anyone who might just be starting a relationship in the night sky.

Some of the easiest objects to find and watch in the sky are the planets, and there is a good reason to have a post about where the planets are right now (and what they are doing), and that brings us to the first planet we will look at, Saturn. Saturn is the sixth planet out from the Sun, and the second largest planet, but the aspect of Saturn that everybody rightfully thinks of is its ring system.

The rings of Saturn are so bright because they are largely made of ice particles, and the diameter of the ring system is over one hundred and twenty thousand miles across – but the rings are only a few miles thick. We can see the rings of Saturn because Saturn’s orbit is tilted slightly compared to the Earth’s, but even with a tilt, there are still two times during Saturn’s orbit around the Sun at which Saturn is in the same plane as the Earth and we look at Saturn’s rings edge on. At these times, the rings seem to vanish altogether! The next time this happens will be in late September, but Saturn will be too close to the Sun to see, so go ahead and look now, if you have even a small telescope, to see Saturn’s rings as a narrow line.



(The disappearing rings were noted by the first person to look at Saturn through a telescope, Galileo, who only saw indistinct shapes on Saturn’s sides. In Greek mythology, the titan Cronos – associated with the Roman ‘Saturn’, although that isn’t really … but I digress – who swallowed his children as they were born to thwart a prediction that his child would supplant him. When Galileo saw “Saturn swallowing his children”, he was so frustrated that he stopped observing Saturn at all.)
Saturn can be found in the west as night falls, south the constellation of Leo. If you are looking above the western horizon, the map below shows you approximately what you would see, without the names and big blue lines. If you have any city lights in the vicinity, then you might just see the stars whose names I have included.



If you want to be sure if you are recognizing the stars correctly, I have included a map from my first constellation blog showing some of the stars that can be found from the Big Dipper. If you can find the Big Dipper high in the sky, then you can follow the two stars of the bowl that connects to the handle along a line that comes very close to the star Regulus.

That’s all we have in the evening, but if you are actually getting up early some morning to look for the space station, or if you just have a time when you can’t sleep, the planet Jupiter (the fifth planet, and the largest planet in the solar system) will be high in the southern sky, and Jupiter will be by far the brightest thing in the area. If you were to look at Jupiter in even a small telescope, the four largest moons of Jupiter (on the same size scale as our own Moon) will appear as a line of stars. The planet Neptune (the eighth planet, about four times the radius of the Earth) is actually very close to Jupiter in the sky right now. If you are able to find Jupiter in a telescope, and you can tear yourself away from the view of the moons, and the bright bands and dark zones of Jupiter’s cloudtops, then you can try and find the planet Neptune to the north and east of Jupiter. Neptune is fainter even than the moons of Jupiter, and shows you as little. While telescopes will show the disk of the planet Neptune, and you can see the strong blue color caused by the methane clouds of Neptune’s atmosphere, that’s all that you get. No matter how strongly you magnify that image, neither Neptune nor Uranus (a little harder to find) will show any features whatsoever. Mark off that you have seen Neptune (hurrah!) and go back to Jupiter.

Uranus is much harder to find, located in the constellation of Pisces, which has no bright stars to speak of. I’ll go into more depth in finding Uranus when it becomes more of a evening star.
Venus and Mars are both morning stars right now, visible in the east before sunrise. Venus will be high enough in the sky to find easily. From Venus, Mars is close to the north, and both should be visible in the same field in binoculars. Mercury, the last planet to rise tonight, will rise shortly before the Sun, and would be very, very difficult to find.

(I’m waiting to get into the whole Pluto thing til its own entry. Pluto is up tonight, but forget about seeing it. My own telescope is too small to see Pluto, and even if I could, it would only appear as a dot. Really, this blog is about Saturn.)

Glossary (Blog #0)

In this “zero-eth” Messier Pro, I am just going to define a few terms that you might not be familiar with unless you’re already familiar with amateur astronomy. I’m going to post a link to this on the side of the page, and I will come back and add to this glossary as I keep finding things that I forgot to define …

ASTERISM:
An asterism is a pattern of stars that is not a CONSTELLATION (which see). I’ll make up patterns of stars to help find some objects off the beaten path, and I’ll introduce some identified asterism as we go.

BRIGHTNESS:
Brightness describes how an object appears from Earth, and so doesn’t actually say anything about the object itself. There are stars that are bright because they are close to us, and stars that put out much more light, but are dimmer because they are farther away.
Brightness is measured in magnitudes, in an idea going back to the Greek astronomer Hipparchus. Hipparchus labeled the brightest visible stars as “stars of the first rank”, and the dimmest stars as “stars of the sixth rank”. Tradition is a powerful force, and this has remained the pattern even as we now have technology able to measure just how much light is coming off of a star. The faintest stars that can be seen with the naked eye (see “named stars”) are sixth magnitude, and first magnitude stars are some of the brightest stars in the sky. The magnitude system is not linear because the eye’s response is not linear. The system is defined such that a star with a magnitude of m = 1.00 provides 100 times as much light as a star with m = 6.00. This means that brightnesses can be unintuitive to the point of frustration. The brightest star, Sirius, has a magnitude of -1.4, the planet Venus can get as bright as -4, and the Sun has a visual magnitude of -26.

CONSTELLATION
A constellation is an arrangement of stars that has long been considered to represent some figure or object. Most cultures had their own set of constellations (some cultures named individual stars, some probably had their own but got culturally co-opted by some other group), but the “official” set was settled upon by the International Astronomical Union (the same people who disqualified Pluto) in 1930 based upon the Roman constellations taken from the Greeks, some of which they took from the Babylonians, Indians, and more. There are 88 accepted constellations.

DOUBLE STAR
A double star is a system in which two stars are actually orbiting around a common center of mass. There are many sets of double stars that are close enough to Earth to make interesting things to see, there are some that are interesting because the orbits of the two stars actually cause them to eclipse each other as seen from Earth, and there are also some stars (called “optical doubles” that have been identified as double stars, but were later discovered to have simply been in the same line of sight, and nowhere near each other.

NAMED STARS
There are about six thousand stars visible to the naked eye in the sky. (I wonder if this is going to mean I get some hits if someone googles “naked”? Hmmm … naked naked naked naked …) Less than two hundred stars have individual names, primarily because remembering six thousand names is a little problematic. Still, the brightest stars all largely have names, and the commonly accepted names are largely from the Arabic. (I am not sure why Greeks named constellations and Arabs named stars. Perhaps Greek navigators didn’t need to be as precise navigating in the Mediterranean as Arabic travelers needed to be in the Indian Sea and aiming for small oases in big deserts.)
When I post star maps, I’ll post the names of all identified stars. If I miss any, I’ll try and fix that. This brings up an interesting point. For some years, there have been companies that allow you to “name” a star for a person. This is official – as far as that company is concerned, but nobody else knows about it. Have something cheaper! If you want to name a star, pick a star that has no name associated with it and send it to me (one per person, please), and I’ll mark it one the Messier Pro maps.

TIME:
When I refer to how the sky will appear on a certain night, unless I specifically refer to a certain time, I will be speaking of a time an hour after twilight has ended. This will generally be about two hours after sunset, and it will change over the course of the year. This “observing time” will be marked on the post, although any descriptions I give will be good for some time before and after “observing time” (unless I refer to something close to the western horizon).

Observing Staellites (Blog # -1)

This is a long one, but don’t worry – you don’t have to read all of it!

Welcome to another somewhat introductory posting, (this is why the posts are still in negative numbers), but one that can hopefully enhance your stargazing straightaway. One of the websites that I have listed among my links is to a site called “Heavens Above”. I’m going to go into more depth on some of the benefits of this site, because it can provide location-specific star maps, and because of its satellite observing tools.

The space around the Earth has become pretty crowded in the fifty-plus years in human-made satellites have orbited the planet. It is a rare clear night on which even a casual observer does not notice an unblinking point of light tracing it way quickly across the sky. Satellites do not give off their own light, but can only be seen due to reflecting the Sun’s light. Given the small size of most satellites, this explains why even those in low orbits (about 600 km, or 360 miles, above the surface of the Earth) are faint when we see them. However, some satellites such as the Hubble Telescope and especially the International Space Station (ISS) can appear to be as bright as the brightest planets because they are in the lowest orbit (so rockets and shuttles from Earth can reach them economically) and both have large solar panels to provide their power, serving also as tremendous mirrors. These satellites can appear brighter than the brightest star, and even brighter than the brightest planet.

As it turns out, summer is an excellent time for observing satellites, even beyond the observation that for many people summer is a much more comfortable time to be outside. The reason for this has to do with the way that satellites are seen. In the diagrams shown, the Earth is drawn as a circle, and the orbit of a satellite orbiting the Earth is shown as a slightly larger circle. (Okay, this assumes a completely polar orbit – an orbit that takes satellites over the poles – but that isn’t too bad of an assumption and it exaggerates the size of a low-Earth-orbit satellite’s orbit. If the radius of the Earth is ten units, then the radius of the Hubble of the ISS is eleven units.) Since satellites are only seen from reflected sunlight, a satellite is only visible when it can see the Sun, but we (on the ground) can’t.

In the summer, as in the diagram on the right, we have short nights because the North Pole is tilted towards the Sun, which also allows much more of a satellite’s path to be visible. The thicker curve demonstrates the arc of the satellite’s orbit during which it is visible from our observing location. (The orange lines represent sunlight. The Sun is far enough away from the Earth that the Sun should best be thought of as a direction, not a point.)

In the winter, when the North Pole is tilted away from the Sun (this is not the Earth wobbling, it is tilted, rotating at an angle to its orbit) we have longer nights, and satellites are visible for less of their time above our horizon. Again, these diagrams are exaggerations, but the differences between the two seasons are still distinct.

To use the tools on Heavens Above, I set up a generic account for this blog, with a number of locations already specified. Once you are at Heavens Above, look under the “Configuration” heading for “Registered User Login” or “Create New Account”. (If the Heavens Above site has one problem, it is the sheer density of options available as a big, long column on the left.) Let’s start at the top under “Configuration”: while you could start by making your own account through “from database”, let’s start by looking at the Messier Pro account. Please click “Registered user login”. The login name I’ve set up for this is “Messier Pro” (yes, there is a space in the middle), and the password is “Hi Harry” (there is a space, and case does not matter). Now you will go to the home page for this account. (The default position for the observing location is Winona, Minnesota; if you don’t live there, click on the first active link under “Configuration” and change your location. I’m starting with Winona and Elbow Lake Minnesota; Green Bay, Wisconsin; Stephenson, Michigan; Philadelphia, Pennsylvania; Chattanooga, Tennessee; Knoxville, Tennessee; and Orlando Florida. If you aren’t in one of these places, feel free to add you own location to this list. (Sure, you could always just start your own account, but then we wouldn’t be “hanging out” together on line.)

There are many options you have from this point; I am just going to describe two now. If you scroll down past “Configuration”, and “Satellites” to “Astronomy”, a few lines down is the option “Whole sky chart”. If you click on this you will be taken to an image of the sky as seen from your location, right now. You can change the entries below the chart to adjust for any time and date, a handy feature.

You can also use this website to find times when bright satellites will be visible. Under “satellites” (no surprise), you can find times to see bright satellites including the Hubble Telescope and the International Space Station, as well as fainter satellites (including the toolbag that was dropped from the ISS some time ago), as well as finding all satellites brighter than a certain limit (the smaller the magnitude the brighter the object – I’ll explain this in my next post). To find a certain satellite, click on the link of your choice. This takes you to a table of visible passes. You can then click on the date to get more details, as well as a map of the path across the sky.

Suppose that you see a satellite, and want to identify it. Well, if I saw a satellite last night and thought to take note of the time and the path, I could click on the “Daily predictions for all satellites …” of my choice, click on “Previous PM” at the top, and work through the satellites of the last night to identify the one that I saw.

As an example, here are the next bright (brighter than any stars out at the time) passes for the International Space Station for each of the locations on the list:

Starting in the Upper Midwest:

Winona, Minnesota:
On Saturday, June 20th, the ISS will appear just over the southwestern horizon at 4:59 AM, stay relatively low to the horizon crossing into the southern sky, then the eastern sky through Capricornus, Aquarius, Pisces, and Cetus, to set in the constellation of Taurus.

Elbow Lake, Minnesota
Not surprisingly, the timing in this list is the same as the Winona pass, although these two towns are far enough apart (Minnesota is a tall state) that Elbow Lake can’t see several of the Winona passes as the path of the satellite over the next week or so will south of Winona more often than north. The ISS will appear at 4:59 AM in the south and hug the horizon to set just north of east. I wouldn’t suggest dragging the family out of bed on a Saturday morning to show them this.

Green Bay, Wisconsin
Green Bay is far enough away from Minnesota to see totally different passes. The ISS will get to about as bright as the brightest stars on these passes, the brighter starting at 3:50 AM on Sunday, June 21st. Like Winona and Elbow Lake, the orbit of the ISS when it passes over Wisconsin will result in the satellite appearing in the south and hugging the horizon to set in the east. At its best the ISS will not be more than 14 degrees above the horizon (overhead is 90 degrees). Sleep in.

Stephenson, Michigan
This is a really bad week to try and see the ISS from the UP of Michigan. The best view comes at 3:33 AM on Wednesday, June 24th. Not a lot to get out of bed for, but the ISS will pass close to Venus and Mars in the morning sky.

In the East:

Philadelphia, Pennsylvania
Again, more morning passes, although if you do have the will to get up for 4:50 in the morning, the ISS will be the brightest point in the sky, it will go almost directly overhead from the southwest to the northeast, it will be visible for nearly eight minutes, and it is a good way to identify the Northern Cross and Cassiopeia.

In the Southeast:

Chattanooga, Tennessee:
As in Winona, all of the bright passes of the ISS will be in the predawn morning. Sorry. However, if you get up on the morning of Sunday, June 21st, at 4:50 in the morning, the ISS will appear close to directly overhead, pass through Pegasus, Andromeda, and Perseus to set in the northeast three minutes later. Yes, this is early in the morning, but it might be the best opportunity on this list.

Knoxville, Tennessee
Still morning passes as we move back to the south, but if you can pull yourself out of bed at 5:33 AM on Friday (June 19th) morning, you’ll have a great view of the ISS covering pretty much the whole sky, appearing in the southwest and setting in the northeast. The pass lasts for about five and a half minutes and gets 67 degrees above the horizon. (The pass of Sunday, June 21st starts at 4:50 with the ISS appearing close to overhead and setting in the northeast.)

Orlando, Florida
It seems that all of the US just gets morning views for the next week, but if you are up at 5:09 on Thursday (June 18th), then you can see the ISS appear high in the south southwest (very close to the planet Jupiter, the only really bright thing in the southern sky) and travel to the northeast.

NEXT POST: Where to find the planets right now!

A User-Friendly Guide to the Universe (Blog # -2)

Welcome to “The Messier Pro”, a blog about the universe as seen from your backyard. First things first though, what the heck does the name mean? It might seem like a very long way to go to make a little play on words concerning my wife’s blog, but at least the name was free, and I get at least one post out of trying to explain myself! That’s a victory … isn’t it? Let me explain the long way …

When I was about seven, I got the first astronomy book I can remember, and I began learning my way around the night sky. In seventh grade, I got a telescope with a lens that was actually smaller than the human eye. (Felt a little silly about that when I worked that out a few years later.) I spent two years working with that, then I moved on to a “department store telescope” which turned out to be a cardboard tube with a single lens at the end. I worked with this for four years, and then got a Schmidt-Cassegrain telescope with a mirror eight inches across for my high-school graduation. Some people got cars; I’ve covered much more distance with my ‘scope, and it’s lasted for more than twenty years. I hope this establishes my bona fides as someone with a little observing experience, and someone who got here the hard way. You don’t have to do that, and I can help.

The blog is named after Charles Messier, an astronomer who lived in eighteenth-century France. Astronomy even a hundred years ago was a lot different than it is now. Consider that even the basic about how stars work wasn’t even begun to be understood until the 1930’s. An astronomer in the 1700’s spent much of his/her (there was some “her”) time mapping the skies and looking for comets. Actually, this was much of the goal; if you discovered a comet, it was named for you, and whoever died with the most comets won. How did one go about, oh, eating, during this time, you ask? (No, really, surely somebody asked that? Anybody?) Ah well, here's the answer: One would find a suitably rich person and ask, “Pardon me, but if you pay for me to have an observatory and look for comets so I can discover them, I’ll tell everyone you gave me dough.” Surprisingly, this worked. It was something on the order of Michael Jordan’s endorsements, with less of a requirement to make public appearances in one’s underwear.

A comet, when it is first discovered, appears as a small fuzzy blob of light. Messier made a list of objects in the sky that appeared as comets (small, fuzzy, indistinct) and yet did not move from night to night, so they did not count as comets. To Messier’s mind, this was a garbage list, stuff to avoid, but we know recognize these as clusters of stars, great glowing clouds of gas, and whole .galaxies. Since I have been paid at various times to show these objects to people, I can claim to be a “Messier Pro”. Too cheesy? Maybe. Let’s move on quickly. (I will also be using items off of another list of object called the “Caldwell List”, made more recently by P Caldwell-Moore for the magazine Sky & Telescope in 1995. I will, when all is finished, try to compile a “Leckenby List” of objects that new observers can find, even when conditions aren’t perfect.

Actually, my first idea had been to write a blog focusing on the night sky as seen from the upper Midwest, but I’ve also gotten interest from a couple of people outside the area, so I thought that I would aim a little more widely. Why write a blog to begin with? Aren’t there many, many astronomy websites out there, many of them listed in the box to right? Why do you need MY electrons spinning out there on the internet? There are many astronomy sites out there now, but I have not found one that combines two assumptions that I will now lay out for you. I wanted to start a site that was accessible to someone who might not have any background in astronomy. There are many of these sites out there too, but I also wanted to combine this with an idea that not everyone lives in laces that have dark skies. My basic assumption is that my typical reader is in the ‘burbs. (If you are lucky enough to live with dark skies, my site will still help you; if you live downtown, it’ll be hard to see anything. Make friends with someone with a sky.) Sure there are also places that will make the sky available to you at times (I do it at my school at least monthly), but this is *your* universe – shouldn’t you get to use whenever *you* want? I think so. This will be aimed so that someone who has not been doing this for thirty-five years will not feel left out in the dark. (Rim shot.)

Many blogs will be tied to something going on in the sky at that time. Over the next couple of months, Saturn, Jupiter, Uranus, Neptune, the Moon, meteors and more will each have Messier Pro entries. My next entry will be about observing satellites, and why it is easier to see satellites in the summer. Many of my blogs will be about constellations; I will work my way through the sky, describing each of the constellations that can be easily observed from the mainland United States, and I will describe the constellations in three “layers”.

The first level of coverage will discuss the constellation as it can be seen with the eye. Hey, even if that’s all you got to work with, there is still a lot that can be gained by looking out at the sky with just your eyes – it’s what we had until 1609. The next level of coverage will discuss what can be seen with binoculars. Now, you won’t need to have huge or really spiffy binoculars (but if you have hem, don’t throw them away!); even small binoculars can greatly expand the universe available to you. The last level will be the small telescope. Did you get a telescope for your birthday or from some long distant holiday that’s just sitting in a closet gathering dust? Did you try to use it, only to get lost as some astronomy book/site seems to assume that you navigate the stars like Galileo, or that you can observe from a mountaintop in a National Park? I’m here for you!

NEXT BLOG: Observing Satellites, and I try to post more images!