Return to the Cloudy Nights Telescope Reviews home page


Observing >> Solar System Observing

Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | (show all)
Tonk
Postmaster
*****

Reged: 08/19/04

Loc: Leeds, UK, 54N
Re: C/2012 S1 ISON new [Re: John Wunderlin]
      #5677561 - 02/13/13 12:00 PM

Quote:

I tried to calculate magnitude and got 16.0 tonight so I don't think my process is right- it shouldn't be getting dimmer.




It *is* getting dimmer. There are numerous reports that its dropped 0.5 to 0.8 mags in the last 3 nights.

One idea - yet to be confirmed - is that it is at a small phase angle at present and the phase angle is is now slowly increasing. This could indicate that the comet has been "unnaturally" bright due to back scattered light off dust particals and the comet is actually returning to its "natural" brightness as back scatter diminishes


Post Extras: Print Post   Remind Me!   Notify Moderator  
John Wunderlin
Vendor - Spike-a Focusing Mask
*****

Reged: 10/01/04

Loc: Mineral Point, Wi
Re: C/2012 S1 ISON new [Re: Tonk]
      #5677567 - 02/13/13 12:03 PM

Excellent! I was hopeful that I could track the magnitude over time, but thought I must be doing something wrong. Thanks much!

Post Extras: Print Post   Remind Me!   Notify Moderator  
Special Ed
Postmaster
*****

Reged: 05/18/03

Loc: Greenbrier Co., WV 38N, 80W
Re: C/2012 S1 ISON new [Re: John Wunderlin]
      #5678323 - 02/13/13 08:40 PM

John & Rich--your images of this very dim comet still out around the orbit of Jupiter (~4 AU) are impressive. Keep up the good work--maybe I'm a weenie but I'm not even going to look visually for this intruder from the Oort Belt until it get closer in. In the meantime thanks for the updates.

Post Extras: Print Post   Remind Me!   Notify Moderator  
canukLX90
professor emeritus


Reged: 12/25/08

Loc: B.C. Canada
Re: C/2012 S1 ISON new [Re: John Wunderlin]
      #5678705 - 02/14/13 02:05 AM

John, Rich: thanks for posting your imaging efforts.
This is a challenging chase with this fuzz ball being so
far out.

PJ


Post Extras: Print Post   Remind Me!   Notify Moderator  
hiro
Pooh-Bah


Reged: 07/17/07

Loc: Tokyo
Re: C/2012 S1 ISON new [Re: canukLX90]
      #5697714 - 02/24/13 02:20 AM

Hi all,

Sky was clear and dark for a while on February 9, 10, 11, and 13, 2013, though the seeing was bad due to the strong jet stream here in this season. I tried imaging of the comet with my small scope, Takahashi FSQ-106ED and extender Q1.6x at D106/F850.

I could get 119 frames of the comet, exposure for 6 minutes, about 12 hours in total. The image of the comet looked tiny, and I scaled it up by 5 times with IRIS hoping that the number may be some help.

Here is the result.
http://www.flickr.com/photos/hiroc/8501810109/

Edited by hiro (02/24/13 02:35 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tonk
Postmaster
*****

Reged: 08/19/04

Loc: Leeds, UK, 54N
Re: C/2012 S1 ISON new [Re: hiro]
      #5697828 - 02/24/13 06:17 AM

Whoa - thats some effort Hiro! Nice result

Post Extras: Print Post   Remind Me!   Notify Moderator  
hiro
Pooh-Bah


Reged: 07/17/07

Loc: Tokyo
Re: C/2012 S1 ISON new [Re: Tonk]
      #5697862 - 02/24/13 08:03 AM

Thanks Tonk,

I planned to try dithering technique with drizzle command of IRIS, but I could not do it this time.
Here is a command list of IRIS and link to dithering technique.
http://www.astrosurf.com/buil/iris/nav_pane/CommandsFrame.html

Edited by hiro (02/26/13 07:20 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
John Wunderlin
Vendor - Spike-a Focusing Mask
*****

Reged: 10/01/04

Loc: Mineral Point, Wi
Re: C/2012 S1 ISON new [Re: hiro]
      #5709312 - 03/02/13 06:30 PM Attachment (32 downloads)

Here's my data from last night. I'll try to calculate the magnitude later today if I have time. This was 18x5min bin 1x1. 10" LX50 @ f/6.3, ST8300.

Edited by John Wunderlin (03/02/13 06:31 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
John Wunderlin
Vendor - Spike-a Focusing Mask
*****

Reged: 10/01/04

Loc: Mineral Point, Wi
Re: C/2012 S1 ISON new [Re: John Wunderlin]
      #5709420 - 03/02/13 07:32 PM

Magnitude 15.4

Post Extras: Print Post   Remind Me!   Notify Moderator  
hiro
Pooh-Bah


Reged: 07/17/07

Loc: Tokyo
Re: C/2012 S1 ISON new [Re: John Wunderlin]
      #5710043 - 03/03/13 07:25 AM

Hi,

C/2012 S1 ISON on February 10, 2013 again.



I have updated the image, scaled up x5 earlier, and it got a little more precise.

Here is the original.

http://www.flickr.com/photos/hiroc/8523305073/

Thanks.

Edited by hiro (03/03/13 07:47 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
canukLX90
professor emeritus


Reged: 12/25/08

Loc: B.C. Canada
Re: C/2012 S1 ISON new [Re: hiro]
      #5723357 - 03/10/13 04:23 AM Attachment (44 downloads)

Very nice effort. Thanks for posting.
There was a clear night here, finally, and I managed to
image the comet. Attached is 5 X 3 minutes at ISO 800.
The object marked at mag 17.5 is a galaxy. The comet is
still over 4 AU from the earth and the sun and is moving
at around 19 arcsec / hour.

PJ


Post Extras: Print Post   Remind Me!   Notify Moderator  
canukLX90
professor emeritus


Reged: 12/25/08

Loc: B.C. Canada
Re: C/2012 S1 ISON [Re: canukLX90]
      #5723359 - 03/10/13 04:27 AM Attachment (39 downloads)

Attached is a crop resized to show a bit more detail. For
this image stack I used the comet versus the stars. The
tail seems quite broad to me with a well defined nucleus.

PJ


Post Extras: Print Post   Remind Me!   Notify Moderator  
buddyjesus
Carpal Tunnel
*****

Reged: 07/07/10

Loc: Davison, Michigan
Re: C/2012 S1 ISON new [Re: canukLX90]
      #5724282 - 03/10/13 04:54 PM

now those pics are going deep. gj

Post Extras: Print Post   Remind Me!   Notify Moderator  
John Wunderlin
Vendor - Spike-a Focusing Mask
*****

Reged: 10/01/04

Loc: Mineral Point, Wi
Re: C/2012 S1 ISON new [Re: buddyjesus]
      #5724546 - 03/10/13 07:23 PM

Looking good guys! I'm clouded out for a few days. I hope I get a chance to see Panstarrs too.

Post Extras: Print Post   Remind Me!   Notify Moderator  
AXAF
sage


Reged: 09/15/04

Loc: New England
Re: C/2012 S1 ISON new [Re: John Wunderlin]
      #5731647 - 03/14/13 05:31 AM Attachment (44 downloads)

Here is my most recent image of Comet ISON, taken on 3/14/13 at 04:30UT. It is a 20 minute exposure using a 0.50-m f/6.8 astrograph and a FLI ProLine PL11002M CCD camera.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Jure Atanackov
super member


Reged: 05/04/10

Re: C/2012 S1 ISON new [Re: AXAF]
      #5732094 - 03/14/13 11:41 AM

I'm beginning to wonder if the early expectations of comet ISON becoming as spectacular as the Great comet of 1680 (some even compared it with the Great september comet of 1882…) were just a bit too optimistic. At this time the comet isn't looking intrinsically very bright. Right now it's about magnitude 15. Its heliocentric magnitude is ~12.0. At the same heliocentric distance (4.5 a.u.), comet PanSTARRS was 1-1.5 magnitudes brighter. Similar to comet PanSTARRS, ISON also appears dynamically new. I can’t help but wonder if ISON will follow PanSTARRS’ photometric development, but perhaps a magnitude or so fainter. Maybe H0~6.5 or so and n~3. On a more positive note, the comet appears quite dusty – its morphology is actually quite similar to comet PanSTARRS at the same heliocentric distance. It has a small, compact coma and a developing dust tail. A very dusty nature of the comet would also explain the brightness bump around opposition, when its brightness would have been increased by backscattering. At H0~6.5 the comet would still be above the Bortle survival limit and still at least 4 magnitudes brighter than comet Lovejoy. So its perihelion survival probably isn’t questionable, but I really wonder if it will become as bright and spectacular as first expected...
CS!Jure


Post Extras: Print Post   Remind Me!   Notify Moderator  
OldDeadOne
Pooh-Bah
*****

Reged: 09/09/06

Loc: West Virginia
Re: C/2012 S1 ISON new [Re: Jure Atanackov]
      #5732607 - 03/14/13 05:30 PM

All we can do is hope that it is spectacular when it is viewable this fall,I know I am I want a nice naked eye with a nice tail comet winking it's eye at me.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Tonk
Postmaster
*****

Reged: 08/19/04

Loc: Leeds, UK, 54N
Re: C/2012 S1 ISON new [Re: Jure Atanackov]
      #5732661 - 03/14/13 06:04 PM

I think you might well be right - those concerns have been expressed on Comets-ML

Post Extras: Print Post   Remind Me!   Notify Moderator  
aa6ww
professor emeritus
*****

Reged: 10/23/11

Loc: Sacramento, Calif.
Re: C/2012 S1 ISON new [Re: Tonk]
      #5740043 - 03/18/13 03:15 AM

I'm looking forward to tracking comet ISON as soon as its observable in my C14. Comets are my favorite objects to track, its the one thing I like to look for every time theres a new moon and I'm out with my largest scope..

...Ralph


Post Extras: Print Post   Remind Me!   Notify Moderator  
BrooksObs
professor emeritus


Reged: 12/08/12

Re: C/2012 S1 ISON new [Re: aa6ww]
      #5740347 - 03/18/13 09:54 AM

I share Jure's concerns about the actual potential for Comet ISON to become a truly spectacular object, at least in the eyes of the average amateur astronomer and likewise the general public. I have little current doubt that it will do at least as well as did Comet Lovejoy last year. However, one must keep in mind that for nearly all its southern observers and the astrophotographers they saw it largely under very dark sky conditions, a situation unlikely to prevail for the average northern hemisphere observer.

For objects like Comet ISON, what is actually seen and the degree of spectacle presented is often highly dependent of the clarity and sky darkness enjoyed by the observers...especially once the comet is a couple of weeks, or more, past perihelion and finally well placed in the sky.

BrooksObs

Edited by BrooksObs (03/18/13 09:57 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | (show all)


Extra information
1 registered and 5 anonymous users are browsing this forum.

Moderator:  Rich (RLTYS), star drop, Mitchell Duke 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 20926

Jump to

CN Forums Home




Cloudy Nights Sponsor: Astronomics