August 2008

Anthony 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 twice this month on August 1st and again on Aug 30th. For August, your best viewing nights will be from August 1st through August 7th, and August 24th through August 31st.

The Star chart below is set for Florence, SC on August 15th at 10 pm.


The Star chart below is set for Florence, SC on August 15th at 10 pm.


Jupiter:
This month even people who have no particular interest in astronomy will notice the bright star like object in the south. The object is the planet Jupiter. Jupiter is the brightest object you will see in August, not counting the Moon. Throughout the month, it will slowly drift to the west (retrograde motion) and then on September 4th, it will stop and reverse to its normal easterly direction. Jupiter is the largest planet in our solar system, and is not a solid object, but a ball of gas; about 90% hydrogen, and 10% helium, with some traces of other elements. This chemical makeup appears similar to our Sun, and some scientists once thought that Jupiter was a star that didn’t make it; a proto-star. However, it is now believed that Jupiter would have to be over 70 times more massive to collapse into a star. Note: The concept of Jupiter as a proto-star was used in the famous Sci-Fi movie, “2001: A Space Odyssey.”

Below is an image showing the size relationship of Jupiter versus the Earth.


Jupiter’s presence this summer is a great reason to take out your telescope. If you have only a small telescope, then it will be a great challenge to try to see the cloud bands on Jupiter’s “surface.” If you fail, try on several nights, and at different times. They should be visible at 25 to 50 power. Remember, as you increase the power, the planet’s disk size will increase, but you will loose clarity. The ability to see planetary detail is often based on upper atmospheric conditions, which are not obvious to our eyes. Therefore, you cannot always tell if it is a good night to view a planet until you look at it through your telescope. Another viewing hint is that good summertime viewing often can occur right after a storm front passes through. Last year I had personally viewed Jupiter on several nights through 25 power binoculars, seeing only a fuzzy disk. Then on one night the bands “jumped” into view.

In addition to the surface bands, it is enjoyable to observe the moons of Jupiter. Jupiter has 63 known moons, of which only four are visible through telescopes. The four visible moons are called the Galilean moons, referring to their discovery by Galileo. The moons are named Io, Callisto, Ganymede, and Europa. Galileo reported finding the moons in January 1610. His telescope was about 16-20 power, and quite primitive. History records that another person, Simon Marius, claimed to have discovered the moons over a month before Galileo, but did not announce his observation. Therefore, Galileo who carefully recorded and reported his observations was given the credit for discovery. Below is a compilation of Galileo’s original sketches.


So, if you become frustrated trying to observe the surface features of Jupiter, then try observing the Galilean moons. You can use your telescope, but all that is required is a pair of binoculars; 7-10 power is sufficient. To easily see the moons, you will have to have a steady hand, or brace the binoculars against a solid object. Most binoculars have a tripod mount, so attaching them to a simple tripod is also an option. The moons will appear as tiny points of light on either side of the planet. Remember, on any given night you will see one, two, three or four of the Galilean moons depending on how many are in front or in back of the planet. Below is an image showing a time this month when all four moons are visible, along with their names. This is a binocular image; in a telescope, the image will be reversed. The time is August 15th at 10 PM, enjoy.


Meteors:
This month is well known for the Perseids meteor shower. The popularity is not because this is the best meteor shower, but because it occurs at a pleasant time of year to be outside late at night looking up at the sky. This shower will peak on the morning of August 12th. Look toward the east and also directly overhead. The presence of a waxing gibbous moon will interfere with your viewing late evening on August 11th, until the moon finally sets at about 1:30 am. This is actually good, because the best time to view meteor showers is between midnight and dawn. Remember, that this is the peak of the shower. In case of bad weather, you should get a good display one night before and after the 12th. Also, don’t forget that for meteor showers use your eyes only; no binoculars, and find a place to lie on your back to prevent neck strain. The Perseids can have a rate as high as 60 to 90 meteors per hour; my personal best was about 60 per hour.

Naked Eye Sights:
Watch Jupiter as it slowly moves to the west through Sagittarius. Check out the Perseids meteor shower from the 11th to the 13th.

Binocular Sights (7 to 10 power):
Try to observe the Galilean moons of Jupiter. Make a simple sketch each night to note the rapid movement of the moons. Also continue to wander through the Milky Way star field above and also to the right of Sagittarius.

Telescope Sights (60-100mm):
Attempt to see Jupiter’s surface bands.

July 2008

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 2nd. For July, your best viewing nights will be from July1st through July 7th, and July 24th through July 31st.

The Star chart below is set for Florence, SC on July 15th at 9 pm.


The summer sky has arrived, and many interesting objects are in the south, along the Milky Way. However, this month there is an interesting event occurring in the western sky. Normally, this time of year the constellation Leo is not a target of interest since it is rapidly setting, and will be totally gone by months end, but there is a “Dance of the Planets” occurring in Leo. Beginning on July 1st, Mars will be right above the bright star Regulus in Leo; use binoculars to see the sharp contrast of colors, white star/red planet. From July 1st on, Mars rapidly moves toward Saturn, and on the night of July 10th, Mars will be very close to Saturn, generating another interesting binocular object and color contrast; red planet/yellow planet. This event is a good news/bad news situation. The bad news is that Leo and especially the two planets will be low in the western sky, setting soon after 10 pm. The good news is that with many amateur binoculars and telescopes, bright planets are much easier to see clearly in twilight skies than when sharply contrasted in dark skies. So, the best approach is to start observing the planets from about 9 pm, until they move down into the horizon’s haze.

One more planetary note: Venus will become the “evening star” this autumn. If you have a clear horizon in the west, you just might get an early view of Venus right near the horizon just after sunset late in the month.


Now let us return to the south, and we have a bright “visitor” this summer, the planet Jupiter in Sagittarius. Its location is shown in the last image below. Jupiter will slowly rise in the southern sky all through July and August. Next month I will spend more time discussing Jupiter.

On any given summer, the southern sky is filled with wonderful sights. First we mark off this region with the two constellations, Sagittarius and Scorpius, shown in the image below. This image is from a dark sky site, and there are several such sites in the United States, far away from cities, where you can see the sky as shown here. Scorpius is one of the few constellations that looks like its namesake. Scorpius with its “J” shape looks like a scorpion complete with claws, a stinger and a red/orange star for heart (Antares). Scorpius is the correct spelling of the constellation and not Scorpio the zodiac sign. To the left of Scorpius is the constellation Sagittarius the archer. Very few people see this constellation as an archer; however, most people see it as the “Teapot asterism” with the handle on the left, the spout on the right, and the triangular lid on top.

In addition to these two constellations, the most prominent feature in this photo is the beautiful Milky Way. In the summer, the southern sky view is toward the center of our Milky Way. The green “+” sign above the spout of the teapot marks the exact center of our spiral galaxy. Near this green “+” sign, astronomers have detected a strong X-ray source known as Sagittarius A* (pronounced A star). It is believed that Sagittarius A* is a Black Hole in the center of our galaxy.

So what do you do on a nice summer evening? You don’t need a dark sky site as shown below, just point your binoculars or a small telescope in the region above Sagittarius and also over toward the stinger of Scorpius and you will see beautiful fields of stars. Try slowly scanning this region first without any charts or plans, and you will find many objects that you know must be star clusters or nebulas. Later you can consult star charts to identify some of the objects you discovered in this region.


The following image shows 14 Messier objects in this region and the location of the planet Jupiter, but there is much more to see in this area with only binoculars or a small telescope (can you see Sagittarius and Scorpius in the image?).



Naked Eye Sights:
Say goodbye to Leo as it sets in the west, but take time to observe Mars as it quickly moves from the star Regulus on July 1st to nearly touch Saturn on July 10th. Try to spot Venus right after sunset toward the end of the month. Locate Scorpius and Sagittarius. Also notice that Cygnus that set in the west last November is now moving up from the East to directly overhead (zenith).

Binocular Sights (7 to 10 power):
Scan the western skies from July 1st until July 10th, and note the interesting color comparisons of red-orange Mars, white Regulus, and yellow Saturn. (Between 9-10 pm)
Spend most of your time this month scanning the regions above and to the right of Sagittarius. See how many Messier objects you can find.

Telescope Sights (60-100mm):
Target of the month: the planets Mars and Saturn as they nearly touch on July 10th.

June 2008

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 3rd. For June, your best viewing nights will be from June 1st through June 8th, and June 24th through June 30th.

The Star chart below is set for Florence, SC on June 15th at 9 pm.


I see June as a “quiet” observing month. While waiting for the arrival of some of the great targets of July and August in the region of, and above, Scorpius and Sagittarius, we can return to the Messier objects and locate some of the more difficult targets. In general, the Messiers are called DSO’s (deep sky objects), meaning that they are beyond our Solar system, and most of the Messier objects are within our Milky Way galaxy, the farthest being about 68,000 light years (globular cluster M75). However, a total of 40 Messier objects are truly deep sky objects, and are actually other galaxies well outside of the Milky Way. A total of seventeen of these galaxies are about 50 to 70 million light years away! Remember, our Milky Way galaxy is “only” 0.1 million light years across. Also remember that one light year is 6 trillion miles. If you have trouble conceiving these amazing distances, you are not alone. Where in our world a long drive is five to six hundred miles, and a long plane flight is three to five thousand miles, no one can really comprehend millions of light years.

It is interesting to note that although these distant Messier galaxies were discovered in the late 1700’s, it was not until the 1920’s that astronomers were shocked to realize that these fuzzy objects were outside of our galaxy. Edwin Hubble and Milton Humason discovered this fact while using special stars called Cepheid variables to determine star distance.

So it is time to try to locate some of these distant galaxies. First a note to any new amateur astronomers: Please don’t expect to see deep sky objects looking anything like a Hubble telescope image. Even if you have spent significant money on a telescope, the objects are often seen as white fuzzy objects. Only with expensive camera equipment and long time exposures using various filters can an amateur obtain beautiful and colorful images of deep sky objects.

Now, let’s try to find two relatively easy distant galaxies, M81 and M82 in the constellation of Ursa Major. M81 shown below is a bright grand design spiral galaxy filled with extensive new star birth. Grand design galaxies are those showing a “perfect” spiral structure. Only about ten percent of all known spiral galaxies have this designation. Although it was listed by Messier, M81 was originally discovered by Johann Bode, and is often referred to as “Bode’s Galaxy.”


M82, shown below, is dimmer than M81 and is also known as the “Cigar Galaxy,” which you will under stand from the photo. M82 is seen edge on, and has always been listed as an irregular galaxy. However, a recent observation in 2005 using infrared has detected some spiral arms. Also, observation with other large telescopes has shown that this galaxy is being deformed/pulled apart by gravitational forces from its larger neighbor M81.


M81 and M82 are both about 12 million light years away and are gravitationally linked.

So now let’s try to find them. Although I chose these galaxies because they are relatively bright objects, the downside is that they are sometimes hard to find because they are in a region that has no marker stars to help out. The good news is that being in the constellation of Ursa Major (home of the Big Dipper) they are circumpolar objects, therefore are visible all year long. However, they do get close to the horizon in August and September. Use a pair of binoculars to locate these galaxies, seven to ten power will be fine, and you will be able to see them both in the same field of view. This time of year, they are aligned in binoculars as is shown below, with M81 on the left. Of course, through binoculars, they will be tiny fuzzy objects, but you will still see their shapes.


Below is a star chart to help you out. Draw an imaginary line in the Big Dipper from Phecda to Dubhe, and extend the line out the same distance again. Be patient, keep away from city or neighborhood lights, and if you don’t have a steady hand, you may want to brace the binoculars against a tree, house, car, etc, or place you binoculars on a tripod. Good luck.



It is important to note that although the Messier objects contain 40 distant galaxies, there are at least 400-500 other non-Messier galaxies that are in range of large amateur telescopes. Therefore amateurs can busy themselves for many years searching for these “faint fuzzies.”

Naked Eye Sights:
Enjoy the rising of Scorpius in the south and Cygnus (the Northern Cross) rising in the east.

No major meteor showers are listed for this month. However, a lesser-known meteor shower is the Bootids. In recent years, there have been some outbursts of meteors reported for the Bootids. In June, Bootes is directly overhead, and the weather is warm, so lie down on a blanket or lounge chair on the night of June 26th, and hope for a good show.

Binocular Sights (7 to 10 power):
Your challenge this month is M81 and M82 as described above.

Telescope Sights (60-100mm):
Try for M81 and M82. Be sure to start at low power.

May 2008

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 5th. For May, your best viewing nights will be from May 1st through May 8th, and May 23rd through May 30th.

The Star chart below is set for Florence, SC on May 15th at 9 pm.


Of all the bright stars we see each night, Arcturus is quite unique; but first, I must digress. All of the stars we see on any night are in our own galaxy, the Milky Way. The shape of the Milky Way galaxy is a closed spiral about 100,000 light years in diameter. Our solar system is about two thirds the distance out from the galactic center, and the Milky Way galaxy is spinning at about 600,000 miles per hour, taking about 225,000 years to make one rotation. Our Sun, and “all” of the stars we readily see at night are moving along together, except for Arcturus. Arcturus is moving perpendicular to the plane of the Milky Way! To use an analogy, almost all of the stars we see are like leaves floating together on a river. However, Arcturus would be like a rock dropped off a bridge into the river. The movement of stars in relation to other stars is called proper motion. So why is the proper motion of Arcturus quite fast, and perpendicular to the plane of the galaxy? Recent evaluation of the stars in our galactic neighborhood has shown that there is a group of stars that are moving downward along with Arcturus, called the Arcturus Stream. Arcturus is the only bright star in this group. The theory is that Arcturus and its companions were likely part of a small galaxy that was captured and pulled into our Milky Way. So after we make the next trip around the Milky Way, Arcturus will be fading from view, moving far below us.


So where is Arcturus? It is bright, and one of the easiest stars to locate. Find the Big Dipper, and then follow the curve of the handle and it will point to Arcturus. The saying is “Arc to Arcturus." If you continue the curve, you will then “speed on to Spica," another bright star.


My description of our Milky Way galaxy brings up another interesting question. Since our Sun and Earth are two tiny specs in the billions of stars in the Milky Way, how can we possibly know what the Milky Way really looks like? Like an elephant flea trying to figure out what an elephant looks like? Actually, the size of the Sun compared to the Milky Way is like the size of a flea compared to the Sun! So how do we know what we look like? We have determined the shape of our Milky Way by looking at many other types of galaxies.

We have observed that there are many types of stars having different sizes, temperatures/colors, and ages. In addition, there are many multiple star systems, exploding stars, and also variable stars which fluctuate in brightness over time. Now, as we observe these different types of stars in the thousands of nearby galaxies, we see patterns develop. Certain types of stars occupy certain types of galaxies in particular ways. We then looked into our Milky Way and observed the patterns of the stars in our galaxy. Based on that information, the available data had shown that the Milky Way was most likely a closed spiral, similar to the photo shown below.


As our ground based telescopes improved plus the new availability of orbiting telescopes, we now have a better sense of what we look like. The most recent data obtained from our orbiting Spitzer infrared telescope suggests that we are not a normal spiral galaxy, but instead, a barred-spiral type galaxy. We now believe that the Milky Way looks like distant galaxy NGC 1073 shown below.


Either way, we feel certain that we are a spiral galaxy and we do have spiral arms. Our Sun is located in the Orion arm, the next arm in toward the galaxy center is the Sagittarius arm and the next arm further out from us is the Perseus arm. So can you as an amateur astronomer “see” these arms? In a way you can. Remember I keep mentioning the fun of locating the various Messier objects. Well, M42, 44 and 45 along with 23 other Messiers all reside in our Orion arm. M8, 16, 17, and 20 all reside in the Sagittarius arm. M1, 52, and 103 reside in the Perseus arm.

Naked Eye Sights:
The most prominent constellation last month and this month is Leo the Lion found high in the south. The backward question mark forming the lion’s head and mane along with the clearly defined triangle to the left of the question mark make it an easy target. The bottom star of the question mark is the bright star Regulus. In addition, this month you will see the planet Saturn to the left of Regulus, and Mars to the right.

Binocular Sights (7 to 10 power):
Your best binocular sight of the month will be the planet Mars moving into the Beehive cluster (M44) that we talked about last month. On May 20th, Mars will be in line with the Beehive, so check from May 19th through 21st. Use the star map at the top of the page to locate Mars, to the right of Leo the Lion.

Next find some Messier Objects, and match them to our spiral arms.

Telescope Sights (60-100mm):
Try for both Saturn again, and Mars. However as usual, Saturn is the better target.