Comet Lovejoy to the rescue

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  • Member since
    October, 2007
Comet Lovejoy to the rescue
Posted by Aratus on Saturday, November 30, 2013 4:27 AM

If it hadn't been for all the hype over Ison, then we would be enthusing about a comet actually doing better than predicted - Comet Lovejoy

Lovejoy is circumpolar at my latitude, and visible all night.   Even further south it will be visible for several hours after sunset and before sunrise.    At around 5th magnitude in a dark sky it will be a relatively easy target with binoculars.   Perhaps even naked eye for some people.  

It is located in the North West between the 'Bear's Tail' and the upper stars of Boötes.

That's where I'll be concentrating my observing this evening.

(Antitax mentioned this several days ago, but we were still all mesmerised by the 'comet of the century' Embarrassed

 

Aratus

Location:  North West Devon, UK

-------------------------------------------------

Celestron Nexstar8i (8" SCT).

Celestron Skymaster binoculars 15x70

Other:0.63 & 0.33 correctors. X2 & X4 barlow.

Imagers: Meade DSI & Celestron NexImage.  Canon EOS 550D

 

 

  • Member since
    March, 2008
Posted by Antitax on Saturday, November 30, 2013 6:36 AM

   From MSN Meteo and meteoblue the observing window is between Sunday and Tuesday. Probability of rain over eastern Belgium is 20% on Sunday, 2% on Monday, and 10% on Tuesday. Below 30% it usually means large clearings, and below 20% very dry air. Meteoblue is more accurate and indicates the night between Monday and Tuesday as most transparent and cloud-free.

   Those in northwestern Europe can expect the same kind of weather I guess, give or take a half-day. That includes the southern half of the UK, right Aratus? Large binoculars will pick it up.

TS 8x40 Wildlife, 10x50 Marine/Fujinon 16x70/TS 80mm triplet, 6x30 finder, EQ-3 mount, TS 2" 99% diagonal/Celestron C5+ and 6x30 finder, DIY tripod/5" Bahtinov/12" GSO dob, 8x50 finder/Meade 2" 24mm 82°/Hyperion 24,13,10mm 68°/TS Expanse 17mm 70°/SW 7mm Panorama 82°/Ultima 2x barlow/Astronomik UHC-E filter/Baader O-III/Astro Solar 5" & 80mm filters/Sky Atlas 2000/Rükl's Moon Atlas/Canon 400D/5mW green laser

  • Member since
    October, 2007
Posted by Aratus on Saturday, November 30, 2013 8:22 AM

The weather is looking good for the southern half of England tonight.   However there are swirls of cloud around the high pressure system which I think is going to ruin things for the next few days after that.   There is always a chance of clearer skies in the evening, as long as the fog doesn't return.

70mm binoculars should show a fuzzy star with the hint of a tail.   Recent photographs show a distinctly bluey/green coma indicative of cyanogens.   Good photos have been had with a 135mm lens on an SLR with  5- 15 sec exposure.

For us 50 degree dwellers it will be around 15 degrees above the horizon at 1830 UT, dropping towards the horizon over a few hours.   It then climbs back up again from 2230, and is about 40 degrees+ by dawn.

Friends in Louisiana (and the same sort of latitude - 30 degrees) will not have a good evening view, and will have to wait until around 0230 before it rises.


 

Aratus

Location:  North West Devon, UK

-------------------------------------------------

Celestron Nexstar8i (8" SCT).

Celestron Skymaster binoculars 15x70

Other:0.63 & 0.33 correctors. X2 & X4 barlow.

Imagers: Meade DSI & Celestron NexImage.  Canon EOS 550D

 

 

  • Member since
    December, 2005
Posted by Oliver Tunnah on Saturday, November 30, 2013 9:34 AM

Aratus
Lovejoy is circumpolar at my latitude, and visible all night.   Even further south it will be visible for several hours after sunset and before sunrise.    At around 5th magnitude in a dark sky it will be a relatively easy target with binoculars.   Perhaps even naked eye for some people.  

It is located in the North West between the 'Bear's Tail' and the upper stars of Boötes.

Thanks to houses I had to wait till the wee hours of this morning. I saw Lovejoy at around 3:45am. Even though the sky wasn't as good as the evening before it still presented a good show to my small scope. Worth the look even if you have some city lights to contend with.

  • Member since
    October, 2007
Posted by Aratus on Saturday, November 30, 2013 12:48 PM

Yes, It's pretty low down until the early hours unless you can get it soon after sunset.   I'm pleased to say the forecast was right this evening, and I've had a great observing session.   Lovejoy was Yes !   

The report can be found in the reports section

 (I would have given you the link, but the forum software is messing up the source code - again.Angry)

Aratus

Location:  North West Devon, UK

-------------------------------------------------

Celestron Nexstar8i (8" SCT).

Celestron Skymaster binoculars 15x70

Other:0.63 & 0.33 correctors. X2 & X4 barlow.

Imagers: Meade DSI & Celestron NexImage.  Canon EOS 550D

 

 

Moderator
  • Member since
    July, 2001
  • From: PA, USA, Earth Moderator
Posted by DaveMitsky on Monday, December 02, 2013 3:04 AM

Aratus
 Recent photographs show a distinctly bluey/green coma indicative of cyanogens.

It's been established that the green or blue-green color seen in some comets is due to diatomic carbon or C2.

http://www.astrosurf.com/buil/us/linear-a2/a2_1107010_s.gif

http://www.astrogeeks.com/Bliss/MetaGuide/images/cometvz13.html

http://spaceweather.com/archive.php?view=1&day=22&month=11&year=2013 

Cyanogen or (CN)2, which is commonly referredly to incorrectly as CN (the cyano radical), emits photons at ultraviolet and deep violet wavelengths.

http://www.britannica.com/EBchecked/topic/147747/cyanogen

Dave Mitsky

Sic itur ad astra!

Chance favors the prepared mind.

A man is a small thing, and the night is very large and full of wonders.

  • Member since
    October, 2007
Posted by Aratus on Monday, December 02, 2013 6:41 AM

Yes, I also have come across cyanogen written as 'CN', however you can rest assured that I wouldn't confuse the cyanogen compound with a cyanide radical.Smile

I'll happily concede that diatomic carbon does produce green lines in a comet's spectra, but the overall green hue of a comet can be caused by various substances.  There is a large variation between comets.

A lot of these web sites just feed on the opinion of a particular person they are interviewing at the time, or a few convenient examples.   I would be wary of coming to sole, definitive view on an issue from them.   (Space Weather has also been guilty of the 'CN' = Cyanogen mistake too!)

In the latest edition of the 'Sky at Night' they took the spectra of Comet Lovejoy.  When I get time I intend to examine it more carefully - freezing the frame.  

 

Aratus

Location:  North West Devon, UK

-------------------------------------------------

Celestron Nexstar8i (8" SCT).

Celestron Skymaster binoculars 15x70

Other:0.63 & 0.33 correctors. X2 & X4 barlow.

Imagers: Meade DSI & Celestron NexImage.  Canon EOS 550D

 

 

Moderator
  • Member since
    July, 2001
  • From: PA, USA, Earth Moderator
Posted by DaveMitsky on Monday, December 02, 2013 5:20 PM

I mentioned the fact that cyanogen is misrepresented by astronomers as CN because it appears exactly that way in two of the links that I supplied. This comment was not directed at you.

Here's another example of CN being used improperly:

http://hyperphysics.phy-astr.gsu.edu/hbase/molecule/cn.html

Spaceweather.com no longer makes the fallacious claim that cyanogen can produce green wavelengths (although it still persists in assigning active region numbers to individual sunspots) and the Bad Astronomer Dr. Phil Plait stated a couple of months ago that it's a mistake to say so, as he has done in the past. 

Here are two more cometary spectra, including one of Comet Lovejoy, that clearly show that cyanogen (incorrectly labeled once again as CN) is not responsible for the green (490 to 570 nm or 4900 to 5700 Angstroms) seen in comets.

http://www.astrosurf.com/buil/comet/lovejoy/poster_lovejoy_20131126.png C/2013 R1 (Lovejoy)

http://wela.astro.ulg.ac.be/themes/solar/Comets/Archives/IIb-32.pdf P/1995 S1 (deVico) 

Dave Mitsky

Sic itur ad astra!

Chance favors the prepared mind.

A man is a small thing, and the night is very large and full of wonders.

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