A Delayed Wrap-up , and a New Welcome...

Welcome to a new semester of Astronomy, and of the infamous MW 3-5 Cosmology! The start of this semester was perturbed by some non-before-seen arctic weather in Michigan, but it should all get started on Wednesday. For all the newbies, check my "Welcome Message" to know what we're all about, and for all of those returning in the Cosmology class, welcome back!

The winter nights will offer us many possible clear and crisp skies, in addition to some brilliant constellations visible in our northern hemisphere. We will spend every opportunity we have looking at the sky this semester, and if the start of this week was any indication, we will have nights when it will be extremely cold, so come with extra winter jackets, hats, wool socks, boöts, and don't forget the gloves! Click here for some tips on keeping warm while viewing.

Waning gibbous Moon over OCC-OR "pond" and K-Bldg.
(Nov 20, 2013)

Before we get going here, I would like to make some amends for last semester, as I allowed myself to get caught up in the noisy confusion of life and miss a few blog entries. I decided to sum up the last few weeks of Fall Semester in this blog just to keep the flow going, so here goes!

Stargazing through the haze and clouds. (Nov 20, 2013)

Our last few viewings featured the constellations of Orion, Taurus, and Auriga as the three were rising from the East during the last few weeks of the semester. In addition, Jupiter was finally making its way and we were able to see it rise from the northeast at some point. We've also witnessed how dramatically the sky changes throughout the course of a semester, and some of you will come out this winter and not realize the sky as we last remembered it in late November.

Comet Ison faintly captured in this long
exposure photo.
Notice Mercury too! (Nov 16, 2013)

On November 16 we caught comet Ison, Lovejoy and Encke during our special observing session. That same dawn we also caught Jupiter, Mars, Mercury and several constellations like Orion, Virgo, and Boötes. Those that were able to make it not only enjoyed the awesomeness that was the dawn sky, but also some hot chocolate and coffee as well. This semester, there will be an opportunity outside of class time to view a Total Lunar Eclipse, so keep an eye out for more details as the semester goes by.

Comet Ison (Top and Center) as appeared through the telescope.
It was difficult to focus the image. (Nov 16, 2013)

Jupiter and its four main moons through a telescope.
Notice the colors of Io and Europa - Phenomenal!
(Taken Nov 16, 2013)

The Fall semester provided ample viewing opportunities, and quite the astronomical events such as the arrival and disintegration of comet Ison, a phenomenon that made this event a once in a lifetime. I'm positive the winter skies will provide us with a lot more, so keep looking up and keep watching this space!

Clear Skies!
- SHH

Comet Ison Viewing

UPDATE:

The forecast changed a little, but we should still be okay! The clouds are coming around 6:00 am for a 30% cover, and by 7:00 am it would be 50% cover. Regardless, let's hope that we can view Ison at 5:00 am! Be there earlier than you anticipated!

Saturday's forecast shows some clouds that will roll in by 6:00 am. Earlier
viewing is recommended.

Below is a sky map showing where comet Ison will be in the eastern sky. The best way to locate comet Ison is to find the Big Dipper, follow the arc of the handle to Arcturus (in Bootes) then keep that arc until you hit Spica in Virgo. Comet Ison is right above Spica!

In addition, there will be Mars and Mercury to look at, as well as Jupiter in the western part of the sky. The almost full Moon will be setting in the west at that time, and there is a possibility of spotting some meteors (part of the Leonid meteor shower). So even if we don't spot Ison, there will be plenty for us to see!

Eastern skies about an hour before sunrise - Note how many comets there are!
Mercury and Mars should also be visible.

See you tomorrow! CLEAR SKIES!!!

SHH

Comet Ison Viewing UPDATE!

Comet Ison Viewing UPDATE!

Friday morning is looking CLOUDY so we won't observe on that morning.

Saturday however is forecast to be CLEAR! If you can make it to OCC at 5:15 / 5:30 am , then you should! I will be there at 5:00 am to setup (you're welcome to come early too).

Clear skies forecast for Saturday morning at 5:00 am. Temperature will be between 28-32 degrees F, and
humidity a little high which will make the transparency below average, but we should be okay.

We will meet on the Orchard Lake side of campus, by M-Building where the traffic circle and flag pole is. There's the short term parking lot (Parking LOT 5) where you can park.  We will probably stand at one of the traffic islands there marked by the red star on the map below

Map of OCC-OR. Meet at red marker - park in LOT 5.

Please dress for the weather, it will be cold, but comet Ison is now visible with the naked eye so it's worth it! Hope to see some of you there! (There will be coffee / hot chocolate, donuts, and a bunch of binoculars and telescopes)

The Phases of Venus

Venus through telescope on July 10, 2013
Taken by Samer Hariri @ OCC-OR

One of the many observations that Galileo made in support of a heliocentric model of the solar system was on the phases of Venus. One might ask, how can you conclude from observing and recording the phases of Venus over a period of time that the Sun is at the center and that Earth along with all the other planets are orbiting it? Galileo had an understanding of moving bodies, and by using simple geometry he was able to confidently support a heliocentric model once his observations matched his predictions. To truly understand this thought process, one must attempt to draw out what the phases of Venus would look like to Earth in both a heliocentric and a geocentric model. Of course to create such an attempt requires an understanding of how planetary bodies like Venus or the moon can have phases in the first place.

The phases of Venus as drawn by Galileo.
Galileo Galilei, Il Saggiatore [The Assayer] Rome, 1623.
Image obtained from http://brunelleschi.imss.fi.it/

Full Moon during the Oct 18, 2013
partial lunar eclipse. (aka Hunter Moon)
Taken by Samer Hariri

On October 18, 2013, there was a partial lunar eclipse visible here in Michigan. During that eclipse, the Moon was in it's full phase, and was passing through the penumbra of the Earth. The difference in brightness was hard to depict for this partial eclipse but with high quality imaging techniques, one would surely see a difference (click here for example). So why do eclipses happen, and how are they related to the phases of the Moon? When we look at the diagrams showing how the phases of the Moon occur, we notice that during a full phase, the Earth is in between the Sun & Moon. During a new phase, the Moon is directly between the Earth & Sun. When this happens, we are unable to see the moon in the sky because the side that is lit by the Sun is facing away from us. During these two phases (full & new) is when lunar (due to full) & solar (due to new) eclipses are possible. A crescent phase occurs when the Moon is waning into a new phase, or waxing out of a new phase. This occurs when it's location is almost in between the Earth & Sun but not completely. The Moon is either a waning or a waxing gibbous when it is closer to it's full phase location. We know that the Moon orbits the Earth, and by understanding its motion about the Earth we can predict its phases quite accurately.

Diagram showing the location of the Moon and its corresponding phases as it orbits the Earth.
Note how the location of the Moon is different from new phase to new phase (green shaded area).
One would expect it to start and end in the same location as it cycles through its phases but it doesn't. Why?
Image obtained from Wikipedia.

      

Phases of Venus in relation to its orbit
around the Sun as seen from Earth.
Image obtained from Wikipedia.

Similarly, if we were to draw Venus along its orbit about the Sun, we can predict the phases we would see of it. As you look at the diagrams showing the location of Venus in relation to what phase we see of it here on Earth, think about how similar that is to the phases we see of the Moon, but more importantly what difference there are. For example, the possibilities of locations in this case can never have the Earth be in between Venus and the Sun. This means that we can never see a full phase of Venus on Earth. However, if we were to base our prediction on a geocentric model then would we expect to see a full phase of Venus, if any? The answer is yes we would since the orbits would eventually have an order where the Earth is now between the Sun and Venus, and we would be able to see a full phase of Venus, and possibly a Venusian (or Venerian if you'd like) eclipse! When Galileo realized that he is not able to witness a full phase of Venus, he immediately knew that the Sun was at the center of our solar system. In addition, the apparent size of the phases indicated that Venus was indeed orbiting the Sun inside the orbit of the Earth. Think about where Venus is during each phase, and what the size of that phase is as drawn by Galileo and if that makes sense or not.

Images of the phases of Venus taken through the Jaicoa Observatory. The image
shows the phases of Venus over a period of time and depicts nicely how the size and shape changes.
Image was taken by Efrain Morales Rivera and was obtained from http://www.jaicoa-observatory.com

Finally, think about the other planets and what phases of those planets we are able to see. What phases do you think Mercury would exhibit? What about Mars? Would we ever see Mars as a crescent here from Earth? It's amazing how by simply observing the various phases of planetary bodies here from Earth, we are able to explain accurately the location of these planetary bodies with relation to Earth. We were able to construct a fairly accurate representation of our solar system some 400-500 years ago by simply looking up at the night sky and "reverse engineering" what we saw into models and diagrams that make sense. The best out of a lot of these early models of our solar system were the ones that explained a lot of the phenomenon (like phases of Venus, retrograde motion, etc..) in the most simplistic manner possible. I sometimes wonder if I would have had the capacity to come to the same conclusions Galileo, Copernicus, or the various others came to about our solar system simply based on the observations they made. It makes sense to me today, and it seems to be relatively elementary, but I'm not sure if I would be as brilliant to initially think of something that is so simple, yet so profound if I had lived in the times of Galileo Galilei...

SOL

DISCLAIMER: NEVER LOOK AT THE SUN THROUGH A REGULAR TELESCOPE - EVER! Blindess will befall on you in less than a second. Always use a solar telescope designed for solar viewing. Internal blocking filters in such telescopes reject all unwanted and harmful radiation, for completely safe viewing.

The Sun through a solar telescope.
Note the prominence loop.

This evening during study group we went outside to safely view the Sun. We used a Meade Coronado Personal Solar Telescope with an H-Alpha filter that allowed us to see amazing prominences and surface features of the Sun. In addition, we used the 4.25 inch AstroScan with a screen to view the reflection of the Sun. The sunspots were evident and it was a great experience for those that have never seen the Sun through a solar telescope before.

A prominence is a loop of plasma that extends out of the Sun and back. It is often very large in size, and you could probably fit dozens of Earths within it. We were lucky to not only witness a prominence in our Sun today, but to actually watch it change. Initially, the prominence had a complete loop which later on broke, and minutes after that faded away entirely. Prominences are actually plasma ejections from the Sun that get trapped within the magnetic field lines (which is why it loops around and spirals back towards the surface of the Sun). 

Astronomy students safely viewing the Sun through a solar scope and a screen.

The reflection of the Sun on a screen.
Note the sunspots.

We also witnessed a few sunspots both in the solarscope and the reflection from the Astroscan. Sunspots are regions that are relatively "cooler" in temperature than the rest of the surface of the Sun. Prominences are actually associated with sunspots except we don't see the prominences in this case because the surface is facing us directly. Both these phenomenon are driven by magnetic field activity from the Sun, and both are associated with solar flares and coronal mass ejections, two primary events responsible for auroras. As a matter of fact, there was a solar flare earlier today that will reach the Earth later tonight and will cause auroral activity for regions in Northern latitudes and possibly low on the horizon in the Upper Peninsula of Michigan. Astronomers usually use an index to determine the strength of an auroral activity called the Kp. For us in Michigan, a Kp of 7 means northern lights will be visible at our latitude.

Astronomy students and Marc viewing the Sun through a solarscope.

Angela looking at the reflection of the Sun from the Astroscan.
The color is green because we were using an O-III filter with a polarizer.

Our Sun is a very dynamic star, and to be able to witness all the activities that occur on its surface is quite the experience. That ball of gas is the reason we exist on this planet. Without it, we would be one lonely and cold planet that has nothing but ice covering its surface. We are in mid October and yet all of us who shared this experience today felt the warmth of this star and embraced it. There are many mechanisms responsible for Earth being the way it is (sustaining life and what not), and without SOL, none of those mechanisms would even matter.