Bright Xmas Comet 2013?

[deanm (Dean)]

I'd like to back-track to a question Suzy posed a few posts back:

"Will we need to wear solar glasses as it's so close to the sun & will they even work on the comet?"

This is a good point - and connected to it, will the comet be visible through a 'scope-mounted solar filter?

Dean

[Rob_K]

Originally Posted by deanm

I'd like to back-track to a question Suzy posed a few posts back:

"Will we need to wear solar glasses as it's so close to the sun & will they even work on the comet?"

This is a good point - and connected to it, will the comet be visible through a 'scope-mounted solar filter?

Dean

The answer is no unfortunately - solar filters will not transmit enough light to see the comet. Ditto with the 'scope-mounted solar filter'. You're dealing with a perhaps mag -8 comet (if it survives, whatever, who knows) and a -26.9 magnitude Sun. So you're trying to see something that is probably hundreds of thousands of times dimmer than the Sun, albeit in a much smaller 'package'.

Cheers -

[Suzy]

Ian, once again you've been a huge help, thank you so much.

Jarrod I'm so jealous! Lucky you, how awesome!

[OzEclipse (Joe Cali)]

Originally Posted by JB80

Thanks Ian for the reply,

I'm going on the idea that we might be living in France by that time so as far as I can tell the easiest option would be a drive up to the Normandy region on the coast overlooking the channel islands. It seem to be one of the more LP free regions. Depending on what other plans we might have.

The other thing I have just considered is stellarium predicts(the only info I had at hand) Ison to be +6mag on November the 3rd, there is also a total solar eclipse on that day so I wonder if ir might be visible during totality or even able to be captured on camera with a wide enough lense to get the eclipse and comet in.
I imagine it'd need to be a combination of exposures to work.
Just an idea I had.

I wonder what Gabon is like in November?

Hopefully some news soon re the meteor shower, that would be a nice bonus.

I'm picking up a number of posts including Jarrod's.

Using solar filters

As Rob pointed out solar filters are a no go on the comet. Even if Comet C/2012 S1 (ISON) reached a magnitude of -4, an ND4 solar filter drops the brightness by 10 magnitudes and and ND5 filter drops it 12.5 magnitudes. So the Sun at magnitude -26 with an ND5 filter drops down to mag -13.5 - about four times as bright as a full moon but the comet drops down to mag 8. Would you see a mag 8 comet next to a full Moon let alone something as four times as bright as a usual full moon?

However you could try using a bare piece of filter as an occulting device. This has the advantage that you can see where the sun is with respect to the edge so that the sun is unlikely to peek out and surprise you. Nonetheless extreme caution will be necessary to avoid exposure and I wouldn't try this with optical aids, just naked eye. Another possibility is to use a tall building as an occulting device. Stand just near the edge of the shadow with the comet exposed, Sun hidden.

Observations during Solar Eclipse

Forget it. Based on current predictions, the comet will be around magnitude 6 during next November's eclipse. This is unlikely to be visible except with telescopic aid and frankly there are more interesting things to look at during a solar eclipse than a mag 6 comet. I have picked up mag 6.5 stars in the corona in my photos in the past but the comet is at 50 degrees elongation so it's not likely to pop up in anyone's photos by chance. On Nov 3rd, from the eclipse zone, the comet will be much more easily observed in the completely dark pre-dawn sky. I'll be on a yacht crossing the Atlantic observing the eclipse and finishing in Barbados on the 13th.

However, if like me, you want to go to the eclipse anyway, the geometry just north of the equator is a bit more favourable than the southern hemisphere. Probably not warranting a special trip but if you'll be there anyway, why not? The slight north equatorial latitude results in a short twilight and inclination of the celestial sphere to the horizon pushes the comet higher above the horizon. I am toying with the idea of spending another 2 weeks in the Caribbean touring around (something I wanted to do anyway) and observing the comet from the West Indies, Jamaica and Cuba then flying home around 28/29th. The air at 40000 ft is pretty clear in the unlikely event I can get a good clear window I might manage a glimpse.

The weather in Gabon is pretty bad.

One possibility here at home is to look into a group chartering of an aircraft and flying high to get above all the crud in the atmosphere. I chartered a DASH 8 for the last eclipse. We flew a big group of people out to the Gulf of Carpentaria. It's pretty easy to do and wouldn't cost too much if you were just going to go up and down for a short flight without covering too much distance. A Dash 8 with its high wing is not the aircraft for this. An 8-10 seater low wing aircraft like a Cessana 402c will get you up to 10000 ft without too many layers of glass or plastic between you and the sun. Choose the aircraft carefully. Inspect the windows first. You also have to make the flight early or late so the sun & comet is low enough altitude to be observed out of the windows.

Joe

[Suzy]

Originally Posted by OzEclipse

I'm picking up a number of posts including Jarrod's.

Using solar filters

As Rob pointed out solar filters are a no go on the comet. Even if Comet C/2012 S1 (ISON) reached a magnitude of -4, an ND4 solar filter drops the brightness by 10 magnitudes and and ND5 filter drops it 12.5 magnitudes. So the Sun at magnitude -26 with an ND5 filter drops down to mag -13.5 - about four times as bright as a full moon but the comet drops down to mag 8. Would you see a mag 8 comet next to a full Moon let alone something as four times as bright as a usual full moon?

However you could try using a bare piece of filter as an occulting device. This has the advantage that you can see where the sun is with respect to the edge so that the sun is unlikely to peek out and surprise you. Nonetheless extreme caution will be necessary to avoid exposure and I wouldn't try this with optical aids, just naked eye. Another possibility is to use a tall building as an occulting device. Stand just near the edge of the shadow with the comet exposed, Sun hidden.

Joe, that is fantastic advice! And thank you so much for such a well detailed, informative post.
I can use my solar glasses held out to block the sun out .
Or I guess if I wanted to get really serious, I could cut out a big square of solar film and mount it on a rigid cardboard frame on a long stick so my arms don't get sore.
Or a large book I'm thinking.
And perhaps even a neighbours roof top depending on the height (I don't have a tall building).

[astroron (Ron)]

Originally Posted by Suzy

Joe, that is fantastic advice! And thank you so much for such a well detailed, informative post.
I can use my solar glasses held out to block the sun out .
Or I guess if I wanted to get really serious, I could cut out a big square of solar film and mount it on a rigid cardboard frame on a long stick so my arms don't get sore.
Or a large book I'm thinking.
And perhaps even a neighbours roof top depending on the height (I don't have a tall building).

Some good suggestions there Suzy
Cheers

[Ian Cooper]

Just commenting on some great thoughts since I last posted here.

Joe, those are some great ideas regarding using solar filters to hide the sun. I also agree that people should not take their eye off the prize when it comes to what to look at during the totality part of a TSE. For that it is all about the corona and any possible naked-eye prominences. Yes keep an eye out for the incoming lunar shadow but concentrate on getting the best possible view of the corona etc. Bino's are safe during totality. Some of the best photos from the Cairns TSE really show the wealth of detail that an observer can burn into their memory. Try and automate as much of the photography as possible so that you can concentrate on viewing the eclipse.

Jarrod, another possible viewing spot could be on the coastal islands on the Dutch north coast. This is where the keen Dutch aurorae observers go to get a true dark northern horizon. Best of luck with all of that.

A spell of clear weather is on the way for me so I hope to get up and catch PANSTARRS at some stage over the next few days to see how that one is looking against the predictions. I'll post on the appropriate thread if I have any luck.

Ian

[JB80 (Jarrod)]

Joe,
It was just a thought I had. I suppose if ISON was near it's brightest it would make for a interesting sight but as you say there is other things happening so it wouldn't be worth trying to hunt it down.

I'd love to get to see the eclipse anyway but if I'm completely honest I think the best we can hope for is to travel to see only a partial eclipse. Central Africa doesn't exactly fill me excitement, even if it is an amazing place.
A yacht would be nice, lucky you.

Ian,
I have had a passing look at those islands before for another reason(can't remember what though).
It will probably be a matter of geography in the end and whatever the best option is closest.

[OzEclipse (Joe Cali)]

Originally Posted by JB80

Joe,
It was just a thought I had. I suppose if ISON was near it's brightest it would make for a interesting sight but as you say there is other things happening so it wouldn't be worth trying to hunt it down.

I'd love to get to see the eclipse anyway but if I'm completely honest I think the best we can hope for is to travel to see only a partial eclipse. Central Africa doesn't exactly fill me excitement, even if it is an amazing place.
A yacht would be nice, lucky you.

Ian,
I have had a passing look at those islands before for another reason(can't remember what though).
It will probably be a matter of geography in the end and whatever the best option is closest.

Here's another idea for a visual aid. Put a solar filter at the center of a 50mm or 100mm opaque disk. A scrap piece of dark coloured mat board from a framing shop would be ideal. Accurately cut a hole at the centre and tape a black polymer filter - say half a pair of solar filters over the hole. Screw the whole disk to the end of a broom handle or a piece of 42x19mm pine from the hardware. At these distances from the disk mark these angles. Sight and centre the sun in the filter and you'll have a calibrated angle device for both position angle and angular separation from the sun. The image of the Sun through the filter will also give your eye an infinity object to focus on. Infinity focussing your eye is always a problem when looking for daytime objects.

In the long version you'll need to support the disk end of the contraption to stabilize it. Not a bad idea for the short one either. A 1/4 inch whitworth T nut would enable the short version to be mounted on a tripod perhaps perched on the roof of a car or attached to a tracking mount.

100mm disk
Angle degrees.........Distance from disk(mm)
8 ..........................716
7.5........................763
7...........................818
6.5........................881
6...........................954
5.5.......................1041
5......................... 1145
4.5.......................1273
4 .........................1432
3.5.......................1636
3..........................1909
2.5.......................2291
2..........................2864
1.5.......................3819

50mm diameter disk
Angle degrees........Distance from disk(mm)
8..........................358
7.5.......................381
7..........................409
6.5.......................440
6..........................477
5.5.......................520
5..........................572
4.5.......................636
4..........................716
3.5.......................818
3..........................954
2.5.....................1145
2........................1432
1.5.....................1909
1........................2864

PS : The boat is technically a yacht. Although I love sailing, I won't be hoisting spinnakers on this trip
http://www.eclipsetours.com/upcoming...tlantic-ocean/

So apart from a talk they've asked me to give during the ocean crossing days, I'm just going with a few friends, kick back and let someone else do all the work this time.

Joe Cali

[JB80 (Jarrod)]

Originally Posted by Ian Cooper

Hi Jarrod,


Not sure about any possible meteor shower. There will be someone working on that right now if there is any possibility.

http://www.youtube.com/watch?feature...&v=_eSYxvUWwVk

"Unprecidented double whammy" meteor shower in Janurary 2014?

Although they did go on to say the odds are you may not see much at all.
Time will tell.

[Suzy]

I came a across this a few days ago- here's more information on the Ison meteor shower:
http://earthsky.org/science-wire/com...-meteor-shower

Wiegert notes another curiosity: “The shower is going to hit our planet from two directions at once.”
When Earth passes through the debris stream, we will encounter two populations of comet dust. One swarm of dust will be following the Comet ISON into the sun. Another swarm will be moving in the opposite direction, pushed away from the sun by solar radiation pressure. The streams will pepper opposite sides of Earth simultaneously.
“In my experience, this kind of double whammy is unprecedented,” says Wiegert.

[glenc (Glen)]

"From January through May Comet ISON brightened hardly at all, remaining stuck at magnitude 16 or 15 and falling nearly two magnitudes behind the early predictions. It became lost in twilight around the end of May and won’t be back in view until the end of August.
So my forecast is that Comet ISON will develop more slowly in the [Northern] autumn morning sky than initially thought. It won’t reach naked-eye detectability until around the 10th of November, about three weeks before rounding the Sun. It will brighten steadily but not exceed 2nd or 3rd magnitude before disappearing into the morning twilight just a week shy of its November 28th perihelion. At that time a short, not particularly bright tail should trail the comet’s intensifying coma.
On perihelion day the head of the comet may spike very briefly to around magnitude –6, brighter than Venus. It might be seen in the daytime sky as a fuzzy point by experienced observers who use great precaution when looking for the comet close to the Sun. This grandeur will persist for only for a matter of hours, as the comet will immediately begin to fade dramatically..."
by John Bortle
http://www.skyandtelescope.com/commu...211408441.html

[Liz]

Comet C/2012 S1 Ison has been recovered by amateur Bruce Gary in Arizona, after being unobservable for a time, it has been estimated at mag 14, and is in our early morning skies.

The next few months will be VERY interesting!! Looking forward to hearing of its development, or lack thereof.

[JB80 (Jarrod)]

http://www.brucegary.net/ISON/

Oooh, thanks for the heads up Liz.

[astronobob (Bob)]

http://www.skyandtelescope.com/news/...219432571.html

[glenc (Glen)]

This map from GUIDE 9 shows Comet ISON on 8 Nov at 4 am looking NE and its trail after that. ISON is near the galaxy NGC4697 on 15 Nov, near Spica on 18 Nov and next to the Sun on 28 Nov. New Moon is on 3 Nov, full Moon on the 18th.

The second GUIDE 9 map shows ISON's path starting on 1 Oct at 4am.

[DigitalNightOwl (Peter)]

Looking forward to ISON. Heres hoping that my jaw will truly embed itself in the ground :-)

[RobF (Rob)]

So, if we miss it in Oct and Nov it won't be visible afterwards from the Southern hemisphere?

[astroron (Ron)]

Originally Posted by RobF

So, if we miss it in Oct and Nov it won't be visible afterwards from the Southern hemisphere?

Rob,it will appear in our northern sky low down on the horizon for a while in February being only 10° altitude on the 10th , and around 10.4 mag and getting fainter.
No bright Comet ISON for us after November.
Cheers

[mithrandir (Andrew)]

I took the 4000 odd observations from MPEC, ran them through find_orb and predicted visibility for Sydney. Give or take a few minutes they should be valid for similar latitudes in Aus and NZ.

According to find_orb C/2012 S1 should be visible in the east around sunrise from Sep 23 until Nov 27 2013, and then around sunset in the west from Feb 3 until Feb 26 2014.

Note the times are UTC and in days and decimal days.