We will be viewing the Venus Transit, weather permitting at HJRO this Tuesday June 6th, from 5:45 to 8PM. We will likely open up later for evening viewing as well if the weather cooperates.
The HJRO Transit of Venus event will happen from 5:45 to 8PM at HJRO. There is a chance we might have at least one image of the sun and venus event projected live until 8:30PM. The transit begins at 6PM, so arrive early if you want to have a chance to see the beginning of the transit event. The event ends after sunset, but we can't see that because the sun will set. We may have night time viewing of Saturn later after the sun sets.
I think we will have at least 40 visitors arrive according to early projections, but we might have more. We could have a dozen visitors (a slow day) or maybe as many as a few hundred, it's difficult to say. And the weather may not co-operate. Some FAAC members have stated they may not commit to many viewing events around here and drive off to a sunny part of the country nearby if they see weather predictions showing it sunny away from this area. Astronomers love to view special or rare astronomy events, so that's understandable.
OTHER LOCATIONS WITH OTHER GROUPS VIEWING THE SUN LOCALLY
There will also be two other locations where you can view the transit. Wayne State University in Detroit at 666 Hancock road (RSVP limited seating), or Kensington Metro Park at the boat launch, with several astronomy clubs there with telescopes. All these events start before 6PM. If you are in the Lincoln Park or downriver area and want to witness the Venus transit through a telescope, (at least for a short time at the eyepiece), you can visit HJRO. Our observatory is located next to the High School football field and track. Park in the Junior High parking lot and enter through the small gate. We will have at least six astronomers present. There is also a chance that one FAAC astronomer will be in front of the Dearborn police station during the Venus transit in Dearborn. Harold "the telescope man" may be in Dearborn setup by the police station, if the weather permits this.
If we have bad weather we may show you the transit as it's streamed from the web. I don't have all the details of that setup. It may be on a small monitor, not a large screen projection system, if we view it off the web due to clouds or rain. If the sun is not visible you're better off viewing it off the web broadcast at your house. But if it's sunny or partly sunny you may be able to catch part of it live at HJRO.
See www.transitofVenus.org for more details about web broadcasts.
LAST VENUS TRANSIT UNTIL 2117
June 6th at about 6PM local time, the last transit of Venus in our lifetime will occur. If you miss this, and you happened to discover the fountain of youth, you might be able to see the next one that happens in 2117.
During the transit, the planet Venus will pass between the earth and the sun casting a shadow over part of the earth. We can only see part of the event from our location. The shadow will be cast for about six hours. But timing is everything and the time this starts and ends favors some in the Pacific Rim countries like Japan or perhaps Hawaii. The areas west of Michigan will see more of the transit event because it will happen about 3 hours before the sun sets in Michigan. Those east of us will see even less of the transit. If you were in Europe you wouldn't see any of this event. (A couple members of our club actually are flying to Hawaii to view the entire transit there.)
If it's cloudy VIEW IT OVER THE INTERNET
Of course to see the transit you'll need an internet connection if you want to watch it over the net from a webcast. There are several web broadcasts available. To see the event in person, you'll need the proper equipment and good weather. For those of us in the greater Detroit area, there are a few places, probably a half a dozen, but I only know of a few at this time, where people have said they will setup and watch the transit.
You need the proper equipment to safely view the transit. Some people use special glasses designed to allow you to view the sun, they are called eclipse glasses. These are sold by some companies that use special film, (not exposed film or homemade film, which will not work). This film has a coating of materials on or inside the filters that cuts out all the dangerous radiation that would harm your eyes when viewing the sun.
There are some things that DON'T PROTECT your eyes. DO NOT USE these: because they are not safe. Some people have tried to use WELDERS GLASSES to view the sun. Most WELDERS GLASSES are NOT SAFE, and you're better off not using any welders glasses just to be sure your not damaging your eyes. There are 14 levels of protection with welder's glasses numbered 1 to 14. 14 being the strongest. Only OLD FASHIONED GREEN GLASS number 14 is safe. Or newer number 14 rated acrylic welders glass that has a GOLD layer on it. If it is not #14 green glass or rated 14 with a gold layer, it's NOT SAFE. It's better to just AVOID welders glasses altogether.
In the old days people used to put carbon from smoke on glass and use that smoked glass to view the sun. This is dangerous. In theory this might work sometimes, but having a consistent and safe coating on the glass is difficult and the smoke residue can fall off of be scratched. Avoid this. DO NOT use smoked glass.
DO NOT use sunglasses to view the sun. They will not protect your eyes from dangerous radiation. Do NOT use polarizers, they will not protect your eyes.
I was observing the recent partial eclipse of the sun in Allen Park, Michigan near a Meijers parking lot with some other FAAC members. And a guy stopped by as the sun was dropping into the clouds near the horizon. He told me he watched the eclipse in his 'automobile rear view mirror" with the night visor flipped to reduce the brightness. DO NOT use you rear view mirror to view the sun, it will not protect you from harmful UV radiation that will damage your eyes.
Do NOT USE exposed film, that will not protect your eyes.
THERE ARE SAFE WAYS to view the sun. Some are safer than others. Some are safer, because they are built to avoid accidents that could happen if your not thinking and use the equipment wrong. One way astronomers used to view the sun which is safe is "solar projection" that is the use of a pinhole camera or small lens or small telescope that projects the suns image on a piece of white paper. Some refractors in the past more from the 60s or 70s, had "eyepiece projection" setups where a shaft was attached to the telescope tube and it held a black blocking piece of aluminum to create a shadow and a matching white piece of aluminum behind the eyepiece. The telescope user would aim the telescope at the sun, without looking through the finder or through an eyepiece. They would ONLY LOOK AT THE SHADOW of the telescope and move the telescope around until they could see the sun appear blown up on the solar projection screen. They often had a cap on the telescope which had a smaller hole in it to allow less sunlight through. The inside of the telescope or the eyepiece could get hot from a viewing the sun for a long period of time. This worked, but it would bring a sharp beam of light behind the eyepiece and you had to keep your hands and eyes away from the beam close to the eyepiece. It was a focused beam that would spread out and be on the solar screen. The attached screens made this fairly safe. You had to use the solar projection screen for this to work and you were looking at the sun on the rear screen.
You can also view eclipses by using pinhole projection. But the sun is fairly small with pinhole projection methods and that will likely not work very good for a "Venus transit". For a Venus transit you will need a larger image of the sun. You can see the planet Venus pass over the sun using Eclipse glasses and your eyes. You always USE ECLIPSE GLASSES with JUST YOUR EYES. You can't use ECLIPSE glasses with a magnified image, like a telescope or a binocular. Do NOT USE BINOCULARS or telescopes unless you have an astronomer setup your setup and understand and know that the filter system is a safe system.
They also used to have very dense small filters you could put on the eyepiece of a telescope back in the 1950s and 1960s. I had a telescope that came with a sun filter. These filters being small and in the path of the eyepiece, received intense light and heat and could heat up and crack. Do NOT USE an eyepiece filter to filter the sun alone. These older filters are not worth the risk. If you find a filter that is an old eyepiece filter for the sun, which came with one of these old telescopes, smash it with a hammer and throw it away.
The pinhole projector won't work very well. But some people want to see the sun and a Venus transit safely. How do you do this? You can perhaps find a location where astronomers are setting up safe equipment and solar telescopes. These will have the proper filters or solar telescopes designed to safely view the sun.
There are two kinds of filters that are most popular and work safely. These filters work safely if they are not damaged and astronomers should carefully handle and inspect filters before they are used to make sure the filtering system is not damaged.
The first filter which is relatively cheap is called a "WHITE LIGHT SOLAR" filter. These are usually a glass or mylar filter that has a special aluminized coating and other particles on it. The coating may also be a kind of special carbon coating inside a special kind of plastic film. The carbon filters are usually dark and black, and most of them are used in glasses, not on telescopes. Some telescope filters may use these kinds of filters ON THE FRONT large lens or over the front of the telescope. But MOST filters that are WHITE LIGHT filters are mylar and look like aluminum foil. And there are some glass filters that look like mirrors as well. These have a reflective coating and the modern ones often have two coatings, one on each side or inside the glass, to make sure the viewer is protected from dangerous rays of the sun. The coating will only allow a small amount of safe radiation through that you can see safely. All the dangerous rays are removed by the filter.
These filters fit in front of the telescope. Special care should be taken in putting these filters on the telescope and making sure they are secure during public viewing events, and of course with your own eyes. Some covers on telescopes, like lens covers fall off sometimes. A cheaply designed filter, may fall off or fly away when the wind blows on the telescope if it's not secure to the telescope. So astronomers will make sure they have a safe filter setup and often will use tape to tape the filter to the tube, to make sure the filter cannot be easily removed or somehow fall out by accident. It's probably a good idea to have a filter system that SHOWS UP and obviously is on the telescope, not hidden away, where you're not sure the filter is on. White light filters cover the entire front of the telescope and filter all the light they let through to the eyepiece. ANY EYEPIECE can be used with white light filtered systems.
White light filters are more affordable. This means they run anywhere from $10 for the most basic white light filter for the Galleleoscope, to perhaps a $100 for a filter for a 10 inch telescope that might be in an aluminum holding cell with set screws on it. Filters can cost up to $200 easily if they are bigger white light filters.
The sun will appear as a white disk or perhaps a yellow colored disk with a white light filter. You will see sunspots and you will see the disk of Venus clearly through a telescope with white light filters.
There is another kind of telescope that uses a much more expensive filter. This is called a hydrogen alpha or HA filter system. The telescopes that have these can show flares and hydrogen gas blasting off the surface of the sun. You will see granulation and other solar features with a good hydrogen alpha telescope. The HA solar telescope will transmit a very narrow frequency of Hydrogen Alpha bandwidth which is safe for the viewer to look at. It shows gas and promanences blasting off the sun and at times features like cool jets of hydrogen gas which look like thin dark lines as they are above the surface of the sun. Sunspots may be visible, at least the larger ones in a hydrogen alpha telescope. Companies like Meade (Coronado), Lunt, and Daystar make hydrogen alpha filters and telescope equipment that allows astronomers to safely observe the sun. These filter and telescope setups used to cost many thousands of dollars and could only be afforded by those with huge pocketbooks, like universities. Daystar started making more affordable filter systems for telescopes, about 20 years ago. Over time the prices came down, but these filter systems are very precisely created and difficult to make. They are crafted at much higher tolerances than most astronomy telescope optics. There are now much more affordable HA telescope systems the cheapest being small systems offered by Coronado (Meade), like the PST or "Personal Solar Telescope". This telescope can be purchased from telescope dealers for about $700. There is also a small telescope made by Lunt that is a 35mm telescope that costs about $700 as well. These telescopes can go up in price. The Lunt and Meade produced telescopes can go up into the thousands or tens of thousands of dollars. A 60mm HA solar telescope from Meade, Lunt or Daystar can cost $2000 to $3500.
Daystar also makes a solar HA telescope that uses a special kind of filter and rear blocking device called a T-Scanner. These are for the most part more expensive than the dedicated HA telescopes like the PST telescope. These systems may mount on many telescopes, but they require a T-Scanner which is something like a large eyepiece holder that often requires power and an energy rejection filter for the front of the telescope. With ALL HYDROGEN ALPHA systems, whether they are a T-Scanner setup or a normal PST kind of setup, there are TWO FILTERS. There is a filter on the front which can also include separate filters. And there is a second filter assembly for most HA setups called a rear blocking filter on the back of the telescope. The HA system MUST HAVE both filters to be safe. If only one filter is on the HA telescope system it's not safe. This is why it's better to come out and chat with an astronomer at an astronomy event and read up and research solar astronomy carefully before you look at the sun or decide you are going to view the sun.
We will be open for the Venus transit, if it rains or clouds prevent viewing you can see the transit on the web. You can also see it at Wayne State University, if you call up and reserve a seat at their viewing event. They are located at 666 Hancock street in Detroit Michigan. They will have a planetarium and indoor viewing if clouds prevent direct viewing from their rooftop observatory. Wayne State is a good venue if you can get to Detroit to do the viewing and want to see the event even if it's cloudy.
Kensington Metro Park will have a solar observing event, sponsored by GLAAC the Great Lakes Association of Astronomy clubs. This will be at the Kensington Boat Launch site in Kensington Metro Park. There will be a lot of astronomers there and they will have a video screen projecting live video on a screen for group viewing as well as have dozens of telescopes there. You will need a park pass to get into the Metro Park there.
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