Transits of Mercury

Post by **weixing** » Mon Nov 06, 2006 10:31 pm

Hi,
Base on NASA Catalog of Transits of Mercury ( http://sunearth.gsfc.nasa.gov/eclipse/t ... talog.html):
It's from Nov 8 19:12UT to Nov 9 00:10UT which is Singapore Time Nov 9 03:12am to 08:10am.

[qyote]In US, it starts from 215pm till 7pm. [/quote]
That's is ET (Eastern Time) which is UT - 5 after the Summer months. To convert to UT, + 5 hours to it and to convert to Singapore Time, +13 hours.

Anyway, the transit will be at the ending stage by the time the Sun Rise, so good luck to those observing it.

Have a nice day.

mrngbss · Post by **mrngbss** » Mon Nov 06, 2006 10:34 pm

Thanks WEixing!

Whew.. I've invited my colleagues and ex-students along!

Robin Lee · Post by **Robin Lee** » Mon Nov 06, 2006 11:39 pm

It is Thursday morning. The exact time is in this page. http://sunearth.gsfc.nasa.gov/eclipse/O ... 06LC2.html

sforce21 · Post by **sforce21** » Tue Nov 07, 2006 12:16 am

ok thanks, cause they posted the time ut 0.09 8 nov for singapore which can mean 8:09 8 nov singapore time so i abit scared i make mistake on the dates lol....

universe24 · Post by **universe24** » Wed Nov 08, 2006 3:41 pm

Kim Miau wrote:I think I can get the Baader solar film and make one myself. Wee Nghee, are you free to get some for me? I think I will try my best to make a full aperture filter. By the way, is it necessary to have such a large filter for the brightest object on our sky?

*What's the preposition for sky?

IMO, the solar filter's aperture should as big as your telescope diameter. So that you can fully use your telescope resolution. Otherwise, use a small aperture telescope for the event.

Robin Lee · Post by **Robin Lee** » Wed Nov 08, 2006 8:18 pm

I think I am gonna miss this event. I am not in time to buy the Baader Astrosolar Film. I am saving on a PST now. It seems that PST is quite a perfect scope for us living in the equatorial latitude. The Sun always shines here.

jiahao1986 · Post by **jiahao1986** » Wed Nov 08, 2006 8:54 pm

Kim Miau wrote:I think I am gonna miss this event. I am not in time to buy the Baader Astrosolar Film. I am saving on a PST now. It seems that PST is quite a perfect scope for us living in the equatorial latitude. The Sun always shines here.

Hi Robin,

You can't miss this event! The next one will be in 2016!!!

I think you still have an alternative to view this event - using projection.

Simply point your scope to the sun(at this time DO NOT look through the eyepiece), place a whiteboard or a piece of blank paper behind your eyepiece, then you see the projection of the sun's image; because the sun is quite low for this event, the heat might not be high enough to damage the lenses of coatings of your eyepiece, or you can use a thrown-away eyepiece for this event.

Besides, prepare a big piece of black curtain or bedspread, or anything that can shield the sunlight and accomodate you and your scope, use it to keep you and the projection plate away from sunlight around for you to see a much brighter image.

The projection method works with me quite well for 2003's Mercury transit and 2004's Venus transit.

For your saving plan for the PST, my suggestion is, wait for a few more years untill you earn your salary, by which time the price for a larger aperture H-alpha filter may have decreased, then get yourself a good APO and a Solarmax filter, you will get much better image than the PST, the photography potential of this combination will me much better too. Besides, now is the minimum solar activity period, you simply can't expect to see very spectacular prominances this time.

Just my 2 cents worth

Clear skies,
Jia Hao

jiahao1986 · Post by **jiahao1986** » Wed Nov 08, 2006 8:58 pm

In case we get cloudy sky, we still can watch live webcasts. A good one is here conducted in Kitt Peak:

http://www.exploratorium.edu/transit/

Robin Lee · Post by **Robin Lee** » Wed Nov 08, 2006 9:07 pm

I thought the way you mentioned will damge my scope? I saw many articles that eyepiece projection will damage the scope badly. Jiahao, what was your scope when you did the eyepiece projection?

Do you know how much is a PST now? If you didn't mention, I have almost forgotten that the new solar cycle has just begun which means that now is the solar minimum. Am I correct in this state? The solar maximum will be 11 years later, is it?

What about a SOHO for those who doesn't have clear skies for this event?

http://sohowww.nascom.nasa.gov/

jiahao1986 · Post by **jiahao1986** » Wed Nov 08, 2006 9:26 pm

Kim Miau wrote:I thought the way you mentioned will damge my scope? I saw many articles that eyepiece projection will damage the scope badly. Jiahao, what was your scope when you did the eyepiece projection?

Do you know how much is a PST now? If you didn't mention, I have almost forgotten that the new solar cycle has just begun which means that now is the solar minimum. Am I correct in this state? The solar maximum will be 11 years later, is it?

What about a SOHO for those who doesn't have clear skies for this event?

http://sohowww.nascom.nasa.gov/

Hi again Robin,

It's not that bad, it will not surely damage your scope, especially when the sun is low. I used a 3-inch refractor for the last two transits and had no problems.

Anyway your scope is much larger, hence more heat produced. The parts that are most prone to damages will be the eyepiece and plastic parts of your scope. For example, in 1999 when I first tried solar projection with my first scope, a 6cm refractor, the inside of the focuser was burned since it was made of plastic, however, if all the parts in the light path in your scope is made of metal, it's quite OK, but do remember to point your scope away now and then to cool it down to avoid damage.

For your SCT, I don't really recommend this as it may melts the glue at the back of the secondary mirror, but if tommorow is hazy, I think you can have a try

About the price of a PST, it's around S$1000 now. And now is indeed a solar minimum, the last maximum was 2000 if I'm right, so the next maximum will be around 2010. Now begin to save money for then

Clear skies,
Jia Hao