July 2012

Tony Martinez

Each month I will describe sights of interest in the night skies of South Carolina. These sights will be broken down into three sections; what you can see with the naked eye, with binoculars, and with a small telescope. The best time to view the night sky is at and around the times when the Moon is not visible, what is known as a New Moon; which will occur this month on July 19th. For July, your best viewing nights will be from July 7th to the 23rd. The Star chart below is set for Florence, SC on July 15th at 10 pm.

Venus Transit:

The ScienceSouth team and over 130 visitors enjoyed perfect viewing for the June 5th Venus transit of the Sun outside our pavilion at Freedom Florence. Everyone was able to view the transit through our filtered 10-inch Dobsonian reflector, our H1 alpha solar scope, and on a projection screen using our Sun Spotter. We were also pleased to have Francis Marion University astronomy professor Dr. Jeanette Meyers join us. Dr. Myers brought an additional filtered 10-inch Dobsonian reflector, and also supplied everyone present with a pair of special solar viewing glasses. Visitors were told to keep these glasses in a safe place to be reused on August 21, 2017 for the total solar eclipse that will pass over central South Carolina.

The Summer Milky Way:

Each summer I remind everyone that this is a great time to be outside, hopefully at a dark sky site, scanning the summer Milky Way.  If we revisit our place in the Milky Way galaxy we see that we are about 2/3 out from the center. See image below:

As we revolve around the Sun and look out into the southern sky, in the summer we are facing into the center of the Milky Way, and in the winter, we are facing away from the center of the Milky Way. This timing of course is just a chance/random happening. Therefore in the summer, higher concentration of matter toward our galaxy’s center allows us to view more visible stars, nebulas, and star clusters.  Hopefully some of my readers have ready access to local sites where the Milky Way is visible. The only downside for our part of the country is that summer also brings humidity, which can interfere with viewing the night sky. 

If you are a serious amateur astronomer and have never seen a brilliant Milky Way, you should try to plan a vacation to a dark sky site. Many dark sky sites are in areas where other interesting sights are nearby for daytime excursions. Sometimes a dark sky site is so isolated that you have great nighttime viewing, and during the day you sleep late, barbeque, and make new friends with your fellow amateur astronomers. I used to drive 300 miles from New Jersey to an isolated dark sky site in the Allegeny Mountains of northern Pennsylvania, called Cherry Springs state park.  The image below shows the view of the Milky Way at Cherry Springs.

To find a dark sky site you can search the Internet, or look in the advertisement sections of Astronomy magazine, or Sky and Telescope magazine. One of many dark sky web pages is http://www.jshine.net/astronomy/dark_sky/. Below are some images from that site.

The blue “tear drops” are locations of private and public stargazing sites. Direct your attention to the dark blue viewing areas. Notice that the closest blue area to Florence is the Francis Marion National Forest, however, there are no sites there marked as astronomy viewing areas.  The closest good “blue” viewing area is in Georgia, called the Deerlick Astronomy Village, http://www.deerlickgroup.com/; check it out.

Another consideration is to look for dark sky sites near places where you have already planned a vacation. Finally, for the very serious amateur, you might want to plan a trip to Bolivia, South America next July for the Southern Skies Star Party;  http://www.astronomicaltours.net/SouthernSkies/. That is what you would call a true astronomy adventure! This Bolivia Star Party is still on my wish list.

However, it is time to return to Florence. Find the best local viewing site and direct your binoculars and telescopes toward the southern sky. The image below is centered on the constellation Sagittarius better known as the “Teapot” asterism. There are eleven Messier objects shown in this image, along with some NGC (New General Catalog) objects. Also note the location of the center of our Milky Way.

First scan this region with a pair of binoculars. Depending on the darkness of your viewing site, you should be able to spot several of the Messier (M) objects. Often you may only note that your target is too fuzzy to be a star. Certain objects in this image look well through a refracting telescope, such as M6 and M7. Most of the objects are best viewed through a reflector, such as a Dobsonian, or through “Big” binoculars. The most difficult Messier objects in this image are M20 and M21. Note, the Lagoon Nebula M8 is visible to the naked eye at Cherry Springs Park.

This other image is centered on the constellation Scorpius, and adds an additional four Messier objects.

Have you ever looked up at daytime clouds and saw shapes of animals or people? The “cloudy” Milky Way is really millions of stars seen at a distance. Actual clouds in the Milky Way are not white, but black and are made of dark matter blocking off the background stars. Now use your imagination and look for the “dark horse” cloud in the above three images of the Milky Way. If you have trouble locating it, see the image below.

Naked Eye Sights: The summer Milky Way

Binocular Sights (7 to 10 power): As always, continue looking for more Messier Objects to add to your list. In particular look toward the Milky Way’s center in the southern sky.

Telescope Sights (60-100mm): Use a reflector to scan the Sagittarius/Scorpius region.

June 2012

Tony Martinez

Each month I will describe sights of interest in the night skies of South Carolina.  These sights will be broken down into three sections; what you can see with the naked eye, with binoculars, and with a small telescope. The best time to view the night sky is at and around the times when the Moon is not visible, what is known as a New Moon; which will occur this month on June 19th. For June, your best viewing nights will be from June 9th to the 23rd. The Star chart below is set for Florence, SC on June 15th at 10 pm.

Venus Transit:

It is unlikely that any one alive today will ever see this astronomical event again. On June 5th, the planet Venus will pass in front of the Sun; this known as a Venus transit. The next time this occurs will be in the year 2117, and at that time, it will not be visible over most of the United States. However, I did manage to view the last Venus transit.

I have often mentioned the “Dance of the Planets.”  This “dance” is the unique relationship each planet has with the other planets as they revolve around the Sun. In general, the planets and their moons revolve on a plane counterclockwise around the Sun. However, this plane is not perfectly flat like a CD disk. The planets and moons can move above or below the plane of the solar system. A good example is the orbit of our Moon. If our Moon was perfectly aligned to the plane of the solar system, the once a month we would have a solar and lunar eclipse. The tilt of our Moon’s orbit results in somewhat rare eclipses on any given location on Earth.

Below is a diagram of the relationship of Earth’s orbit and Venus’s orbit.

The shapes of the Earth/Venus orbits results in the following sequence of Venus transits of the Sun: Every 8 years-105 years-8 years-122 years-8 years-105 years, etc. Therefore, the last Venus transit was in June 2004, followed by this year and then in 2117.

A Venus transit is not what some people would call a “wow” event. The reason is that viewing this event requires special equipment, and it is best to visit a site where trained astronomers can allow you to safely view the Sun. Of course the transit can be followed on television, and through streaming video to your laptop, smart phone or iPad. 

The actual transit of Venus across the Sun’s surface will take about six hours.  Through any safe solar viewing equipment, Venus will look like a small black disk moving over the surface of the Sun. The image below was taken during the 2004 transit.

Below on the left is a composite time exposure of the 2004 transit, and on the right is a comparison of the two most recent transits.

Finally below is a 2004 image of the “teardrop” effect seen as Venus enter or exits the Sun.

So if you would like to see firsthand this once in a lifetime astronomical event, stop by our ScienceSouth pavilion at Freedom Florence, from 6 pm to 8 pm on Tuesday June 5th. Outside our pavilion we will have three methods of viewing the transit. First is a projection method called the Sun Spotter. With this device, at least four people can view the Sun at the same time. Second we will have a traditional Dobsonian reflecting telescope equipped with a solar filter. Finally, we will have a unique solar telescope called an H-1 alpha, which is normally used to see the solar eruptions on the Sun’s surface, called prominences.  Because the H-1 alpha can see the atmosphere above the surface of the Sun, this device should be the first to detect the arrival of the Venus transit.

If we have rain or clouds, we will have streaming video of the transit inside the pavilion. We also have a digital planetarium Star Lab inside which can follow the transit by way of computer software imaging.

While this is a great amateur event, professional astronomers will be studying this transit very carefully. This transit is of special interest to the astronomers who are searching for exo-planets; planets orbiting distant stars. The primary method used by astronomers to locate planets around distant stars is to observe the effects caused by the planets as they pass in front of the distant star. These effects include diming the star’s brightness, or small gravitational tugging. The Venus transit will act as a model to add more information about the effects of planets transiting distant stars. 

As you watch the Venus transit this month, and notice how tiny the disk of Venus is compared to the massive Sun, you can imagine what little effect an Earth-like planet would have on a distant star. This is the reason most of the exo-planets discovered are much larger than Jupiter, and orbit very close to the distant star. This also explains why we seldom find Earth-like planets revolving around distant stars; not because they don’t exist, but because we can detect them. In reality, there may be thousands of Earth-like planets revolving around thousands of stars. As the late Carl Sagen often said, “Absence of evidence is not evidence of absence.”  

Naked Eye Sights: Using our projection Sun Spotter, the planet Venus transit of the Sun. Warning! Do not use your own telescopes or binoculars to project images of the Sun. Children, and also adults are often attracted to telescope eyepieces, and might unknowingly place their eyes on the eyepiece, which would lead to blindness.

Binocular Sights (7 to 10 power): As always, continue working on finding more Messier Objects to add to your list. In particular look toward the Milky Way’s center in the southern sky.

Telescope Sights (60-100mm: Only with professionally set up solar viewing scopes, the Venus transit. Also, Saturn is at a perfect position for viewing throughout this month.

May 2012

Tony Martinez

Each month I will describe sights of interest in the night skies of South Carolina. These sights will be broken down into three sections; what you can see with the naked eye, with binoculars, and with a small telescope. The best time to view the night sky is at and around the times when the Moon is not visible, what is known as a New Moon; which will occur this month on May 20^th.  For May, your best viewing nights will be from May 8^th to the 25^th. The Star chart below is set for Florence, SC on May 15^th at 9 pm.

Saturn:

The rings of Saturn are finally back in view. The ring position of Saturn will continue to improve every year, and then return to the position you see it this month in about 2021. If you bought a telescope in the last few years, this is the time to take it out. You will be rewarded with excellent Saturn viewing now and for the next nine years. This year, Saturn will be in visible in the night sky after 9:30 pm in early May, and will continue through the end of July. The image below shows the ring positions over a 28 year period.

As you know, Saturn is the favorite planetary target because of its spectacular ring system. Over the years as Saturn tilts in relation to us, we see the rings at different angles. When the viewing angle is at or near zero degrees, the beautiful ring system fades from view; this occurred during 2009 and 2010. 

As amateur astronomers, we regularly view the planets in our solar system. As we point our telescopes into the night sky, the big ball of Jupiter looks quite nice, and the small fuzzy ball of Mars is OK, you can also detect the bluish-green colors of Uranus and Neptune, and some people even enjoy the very fuzzy crescent of Venus; but Saturn is special. You can view hundreds of images of Saturn on the Internet, but there is something magical when your see it through your own eyes. So if you have a telescope, Saturn is a must view beginning this month.

To find Saturn this month, look to the southeast to find the pale yellow planet. If you are in doubt about its location, then turn your eyes to the north. Find the Big Dipper, and then follow the handle of the dipper to “arc to the star Arcturus.” Arcturus will be the brightest object in the east. If you continue the curve from the dipper’s handle, you would normally come to another bright star, Spica. However, now instead of one star, you will see a “pair of eyes!” The “eye” on your right is the star Spica, and the “eye” to your left is Saturn. So this year it is quite easy to locate the position of Saturn. If you have dark skies, you should be able to see the contrast of the blue star Spica with the yellow planet Saturn. The image below shows the position of Saturn in relation to Arcturus and Spica in mid-April; note the Big Dipper in the upper left hand corner.

So what should you expect to see? With standard 7 (or 10) X 50 binoculars, Saturn will still look like a star. With 15 power binoculars (tripod needed) it will look like the star has “ears.” I regularly use 25 X 100 mm binoculars, and the rings of Saturn are then clearly visible. Therefore, any scope you use from 25 power on up will allow you to see the rings of Saturn. Most planets supply a significant amount of light to your telescope, and this should be a positive feature. However, with some simple telescopes, the contrast between the dark night sky and the bright planet can sometimes overpower you lenses. If you have any trouble clearly seeing Saturn’s rings with your telescope, try this simple trick. Try viewing Saturn after sunset, but before it becomes really dark. Now you will see the planet without the sharp contrast with the dark sky. Below are three views of Saturn that are likely with amateur telescopes. The smaller blurry image represents what you might see with a very inexpensive discount store telescope (best to avoid). The other two images represent views from Dobsonian reflectors ranging from 6 to 8 inches. The bottom line is if you own any telescope, you can see the rings of Saturn.

Venus Transit:

Time to prepare for the Venus transit next month; June 5^th. A Venus transit is the rare alignment of the planet Venus with the Sun. During a transit using solar viewing equipment one can see Venus passing across the Sun as a small disk. This event will not occur again until the year 2117. I will discuss the Venus transit in more detail next month, but because it occurs early in the month, I wanted to alert my readers of the event. 

To safely observe this rare event requires special solar viewing equipment. Locally we hope to have public viewings at Francis Marion University and at our ScienceSouth pavilion at Freedom Florence.  Although it is on Tuesday, the transit of the Sun will start about 6:20 in the evening, and can be observed through to sunset. The total transit lasts about six hours, but we can only view it for about two hours on the east coast of the United States.

Naked Eye Sights:  The brilliant Venus slowly sets in the west throughout this month; on the 22^nd you will see a nice pairing of Venus with the crescent Moon. The red/orange Mars will still be visible in the south all month, and of course, the yellow Saturn in the east. 

Binocular Sights (7 to 10 power): As always, continue working on finding more Messier Objects to add to your list.

Telescope Sights (60-100mm: After several years, Saturn returns as your best target throughout May and June.

See you next month!

April 2012

Tony Martinez

Each month I will describe sights of interest in the night skies of South Carolina. These sights will be broken down into three sections; what you can see with the naked eye, with binoculars, and with a small telescope. The best time to view the night sky is at and around the times when the Moon is not visible, what is known as a New Moon; which will occur this month on April 21^st. For April, your best viewing nights will be from April 11^th to the 24^th. The Star chart below is set for Florence, SC on April 15^th at 9 pm.

Return to the Virgo Cluster:

Two years ago I gave a brief introduction to the Virgo Cluster. The Virgo Cluster is not a star cluster, but is a cluster of galaxies; the month of April is usually the best time to view this target. Data from the Hubble telescope estimates there are as many as 1500 galaxies associated with this cluster. This galaxy cluster is also referred to as the Virgo/Coma Bernice’s Cluster.

If you attempt to venture into this realm of galaxies, you are somewhat limited to using a reflecting telescope, preferably a 4 inch or larger Dobsonian, or large binoculars, such as 25 X 100 mm. A 100 mm binocular is actually the same size as a 4 inch telescope. However, dim objects such as galaxies are surprisingly more defined through the binoculars than with the equivalent telescope.

As always when attempting to find galaxies you must find a dark sky location. In our area of the country, five to ten miles outside of any modest size town should be sufficient for your search of the Virgo Cluster. A great viewing location is Lynches River Park. However, unless you are camping at the park, or coming to a Lynches River Star Party, you are not allowed to just bring your telescope to the park. The best choice may be to find a friend or relative who owns farm land.

Once you have chosen a good viewing location, first find the location of the Virgo Cluster, see circle below.

Next, check out the area circled with ten power binoculars. The image below is a good example of what you may see.

So where are the galaxies? With normal 7-10 power binoculars, this region looks like a simple star field. If you look carefully, you will note that several “stars” are somewhat larger and fuzzy. These small fuzzies are some of the many galaxies in the Virgo cluster. Next aim your reflecting telescope near the center of this region shown in the circle above. Starting at about 25 power, while looking through the eyepiece, slowly move your scope outward in an expanding spiral. Every few minutes check your telescope finder to make sure you have not drifted outside the Virgo Cluster region of the sky. This roaming technique is quite different from the normal careful searching for a specific target in the sky. If you have chosen a good dark sky site, and you are careful and patient, you should be able to see many small fuzzy galaxies. This next image is what you may see through your telescope. The yellow circle is the field of view at about 30 power. This image also shows the locations of various other cataloged galaxies. These objects are dimmer than the Messiers, and are assigned a NGC (New General Catalog) number.

The following image is how you could see the Virgo Cluster if you owned great astronomy equipment and used long exposure astrophotography.

What I have briefly described above is how to casually visit the Virgo Cluster of galaxies. If you are a serious Messier Object searcher, then you must revisit the Virgo cluster with more care. There are a total of fifteen Messier Objects near the center of the Virgo Cluster, and three others nearby. You will need a good star chart or computer program to start your search. Below is the star chart that I used to check off each Messier as I personally searched this region. As you can see, the chart lists Messiers, NGC objects and many too dim to be labeled objects in the Virgo region. I started with Messier 60 and ended with M49; logging fifteen Messiers in one April night’s viewing.

From M60 to M49, the black line/arrow shows the exact path I used that night as I worked my way through the cluster. I used 25 X 100 mm binoculars to locate all these objects.

Now it’s your turn.

Meteor Showers:

As you may remember there are only three major meteor showers each year, August, November and December. However, there are also minor showers. This year all three major showers occur on or near a new Moon; maximizing your viewing.

This month has a minor meteor shower called the Lyrids, and it also occurs during a new Moon. This shower peaks late at night on Sunday the 22^nd, but you can also check on Saturday night. You may only see one meteor every 3-5 minutes, or as with any meteor shower we might get a surprise burst of meteors.

Remember, when viewing meteor showers; use only your eyes, no binoculars or scopes. Sit in a lounge chair to save you neck muscles. Look toward the region of the name of the shower; in this case, the constellation Lyra. In most cases, the best time to view is after midnight.

Naked Eye Sights: The brilliant Venus in the west. A red/orange Mars in the south and a yellow Saturn in the east. The only other bright object still in the sky this month is the star Sirius in the southwest.

The Lyrid meteor shower.

Binocular Sights (7 to 10 power): Follow the planet Venus April 1^st through the 4^th as it passes through the Pleiades Cluster (M45).

Telescope Sights (60-100mm: The Virgo Galaxy Cluster; see how many Messier Objects you can find in this region of the sky.

See you next month!