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26 Shadow Transits of Titan

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#1 Arkalius

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Posted 01 January 2009 - 06:00 PM

2009 is the year of the shadow transits of the moons of Saturn. Saturn's rings may be going away this year, but we are gaining shadow transits.

A long time back I took the liberty of finding the details of all of the shadow transits of Titan, and there are 26. I made a list of them with some brief descriptions. The first value is the solar elongation of Saturn at the time of transit. The next value is the approximate local time of Saturn's meridian transit on the day of the event. The next line is a brief description of the event. After that is the date and time in UTC of the event.

167w 0:50
Shadow grazes northern limb, Titan south of shadow and trailing
Feb 24 10:50 to 13:22

176e 23:45
Titan grazes north limb, near shadow and now north of it
Mar 12 9:31 to 13:00

159e 22:35
Titan obviously leading shadow now
Mar 28 8:25 to 12:30

142e 21:25
Distance further increasing
Apr 13 7:22 to 11:56

126e 20:25
Elongated starting shadow
Apr 29 6:24 to 11:20

110e 19:20
More elongated shadow start, with Rhea transit
May 15 5:26 to 10:43

95e 18:20
Elongated again, with Tethys and Dione transits above and below rings
May 31 4:33 to 10:04

81e 17:25
Preceeded by Rhea shadow transit
Jun 16 3:40 to 9:23

67e 16:25
Titan now moving closer to shadow
Jul 2 2:49 to 8:43

52e 15:25
Shadow grazes rings after Titan transits north limb
Jul 18 2:00 to 7:58

39e 14:35
Shadow split by narrow rings
Aug 3 1:10 to 7:12

25e 13:40
Shadow below rings for the first time, rings almost gone, low solar elongation
Aug 19 0:24 to 6:26

11e 12:45
Titan transits invisible rings, Saturn now in Virgo
Sep 3 23:37 to Sep 4 5:36 (followed by Dione shadow transit)

2w 11:55
Titan kisses it's shadow, and is now south of rings
Sep 19 22:51 to Sep 20 4:45

16w 10:55
Saturn near Mercury and Venus in early morning, 15 degree elongation, Titan now trails shadow
Oct 5 22:08 to Oct 6 3:50

30w 10:00
Tethys shadow transit already in progress, Titan grazes south limb
Oct 21 21:25 to Oct 22 2:55

44w 9:00
Titan trails far behind
Nov 6 20:44 to Nov 7 1:55

59w 8:00
Ring shadow is obvious, Tethys shadow transit near end
Nov 22 20:02 to Nov 23 0:55

73w 7:05
Ring shadow still obvious, Enceladus comes out from behind Saturn early in transit, elongated exit shadow
Dec 8 19:26 to 23:50

89w 6:00
Ring shadow remains prominent, elongated exit again
Dec 24 18:50 to 22:45

105w 5:00
Enceladus shadow transt starts near end
Jan 9 18:22 to 21:32

121w 4:00
Shadow grazes southern limb, final transit for the season
Jan 25 18:03 to 20:09


You'll notice that the first 10 or so of these are timed well for viewing in north America.

#2 Pete Gorczynski

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Posted 01 January 2009 - 07:40 PM

Thank you, Arkalius. These look like opportunities to capture some unique images. My guess is that the Titan shadow should be visible in anything larger than 4 inches.

Regards,
Pete G.

#3 Arkalius

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Posted 02 January 2009 - 03:00 AM

Yeah Titan's shadow will be a little tougher than spotting Jovian moon shadows, but Saturn's disc is much less contrasty than Jupiter's so hopefully it will be easier to pick out.

#4 dave brock

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Posted 02 January 2009 - 05:02 PM

Yeah Titan's shadow will be a little tougher than spotting Jovian moon shadows, but Saturn's disc is much less contrasty than Jupiter's so hopefully it will be easier to pick out.


Hi Arkalius.
I observed and video'd a Titan + shadow transit through a 12" dob last ring plane crossing and it was as easy as any Jovian event.
Dave

#5 Chopin

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Posted 04 January 2009 - 07:49 PM

Arkalius, this is an excellent resource! Thank you for posting. :bow:

#6 Jim Rosenstock

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Posted 06 January 2009 - 11:22 PM

Arkalius, this is an excellent resource! Thank you for posting. :bow:


Absolutely! Great information! :bow:

#7 Rick Woods

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Posted 07 January 2009 - 07:29 AM

Thanks, Sam! I'll definitely put this to good use!

#8 Larry Geary

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Posted 08 January 2009 - 12:19 PM

I'm confused. This site has an image of a Titan transit taken yesterday, which is not on your list. And the site claims there will be no more after March 12th.

#9 t.r.

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Posted 08 January 2009 - 01:30 PM

I saw that as well and am alittle confused?!?

#10 SabiaJD

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Posted 08 January 2009 - 04:01 PM

Try this site for more Transit schedules.

http://www.pierpaolo.../satsat_eng.htm

#11 chris go

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Posted 09 January 2009 - 12:51 AM

Hi Larry,

March 12 is probably the last time we will be able to realistically observe the Titan (the satellite itself) transit. After March 12 to July 18, Titan will miss Saturn although shadow transits will continue. The transits will return from July 18 to October 16 but by then Saturn will be very low in the sky and close to the sun.

I played with Winjupos for this.

Regards,
Chris

#12 Arkalius

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Posted 09 January 2009 - 03:23 AM

That is a transit of Titan, not it's shadow (though the image looks like it). If you notice for my second shadow transit description, it indicates Titan is north of the shadow at that point. Since the shadow will be at the north limb at that time, you can surmise that titan won't be transiting the disk of saturn anymore after that for awhile.

#13 SabiaJD

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Posted 10 January 2009 - 12:11 AM

I prepared a presentation for my last club meeting concerning trhe transit of Titan and it's shadow. A snow storm cause us to cancel the meeting.

I used the information from the web sites http://www.pierpaolo.../satsat_eng.htm

and http://www.imcce.fr/

as the source of information. WinJUPOS was used to create a view a graphic picture of the events.

This table list information for my local conditions W75 degrees N 41.5

Date EST Time EST Date UT Time UT Moon Phenomenon Phase Alt. Alt. Sun
2/24/2009 6:25:37 AM 02/24/09 11:25:37 Titan Shadow transit Ingress 12.4 -4.3
2/24/2009 6:39:13 AM 02/24/09 12:39:13 Titan Transit Ingress 9.9 -1.1

3/12/2009 4:51:22 AM 3/12/2009 9:51:22 Titan Shadow transit Ingress 17.7 -17.3
3/28/2009 3:37:30 AM 3/28/2009 8:37:30 Titan Shadow transit Ingress 19.2 -24.8
4/13/2009 2:31:16 AM 4/13/2009 7:31:16 Titan Shadow transit Ingress 19.4 -29
4/29/2009 1:29:48 AM 4/29/2009 6:29:48 Titan Shadow transit Ingress 18.8 -30.2
5/15/2009 12:31:46AM 5/15/2009 5:31:46 Titan Shadow transit Ingress 17.7 -29.1

5/30/2009 11:36:20PM 5/31/2009 4:36:20 Titan Shadow transit Ingress 16.4 -26.3
6/15/2009 10:42:58PM 6/16/2009 3:42:58 Titan Shadow transit Ingress 14.8 -22.5
7/1/2009 9:51:18 PM 7/2/2009 2:51:18 Titan Shadow transit Ingress 13.1 -18.2
7/17/2009 8:13:40 PM 7/18/2009 1:13:40 Titan Transit Egress 20.1 -7.2
7/17/2009 9:01:04 PM 7/18/2009 2:01:04 Titan Shadow transit Ingress 11.3 -13.8
8/2/2009 8:12:04 PM 8/3/2009 1:12:04 Titan Shadow transit Ingress 9.4 -9.6
8/18/2009 7:24:10 PM 8/19/2009 0:24:10 Titan Shadow transit Ingress 7.3 -5.5

5/17/2010 1:22:49AM 5/17/2010 6:22:49 Titan Transit Ingress 12.8 -26.1
6/1/2010 11:55:44PM 6/2/2010 4:55:44 Titan Transit Ingress 17.1 -26.3
6/17/2010 11:04:16PM 6/18/2010 4:04:16 Titan Transit Ingress 15.1 -23.6

And here is an example from WinJUPOS

Attached Files



#14 t.r.

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Posted 10 January 2009 - 10:06 AM

I so look forward to these transits...rare treat! I wonder if timing them like the jovian moons is a worthy project(ALPO)?

#15 SabiaJD

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Posted 10 January 2009 - 11:40 AM

I so look forward to these transits...rare treat! I wonder if timing them like the jovian moons is a worthy project(ALPO)?


Although it is not mention as part of the observations in the ALPO Saturn section ( http://www.alpo-astronomy.org ) I am sure Mr. Benton would welcome them.

#16 Mike Phillips

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Posted 12 January 2009 - 08:37 PM

Great info, thanks for posting here!

Mike

#17 Arkalius

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Posted 22 February 2009 - 05:18 PM

Get ready, people, the first one is coming this week... I'm hoping the clouds go away as I've been waiting for these events for a good while now.

#18 Arkalius

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Posted 24 February 2009 - 06:24 AM

The first transit has begun... go watch! ... if you're not asleep anway...

#19 LivingNDixie

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Posted 24 February 2009 - 09:02 AM

How hard are these to see and what kinf of scope does one need to see these?

#20 erick

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Posted 24 February 2009 - 09:23 AM

Was able to watch much of Titan transit until clouded out. Working at about 350x with a 12" reflector in moderate seeing. Shadow was quite distinctive and gradually Titan itself became visible against the planet. A great experience! Too much cloud now to see if I could spot any shadow from the other three moons also transiting at present.

#21 Arkalius

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Posted 24 February 2009 - 03:06 PM

I was viewing with a 4" refractor. It is tough with this instrument. Next time I will probably use my 11" SCT, but it was doable in the refractor. I had pretty decent seeing though, I probably wouldn't have been able to see it at all if the seeing was any worse.


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