Comete C2019Y4 ATLAS UVEX g1200

Post Reply
Dubreuil Pierre
Posts: 202
Joined: Sat Oct 01, 2011 12:34 pm

Comete C2019Y4 ATLAS UVEX g1200

Post by Dubreuil Pierre »

Bonjour à tous

Après une premiere tentative le 4/04 j'ai tenté de nouveau la comète avec aide et remarques de Christian Buil.
Poses de 1200s au lieu de 600s.

Le panneau d'acquisition cette nuit:
acquisitions cette nuit
acquisitions cette nuit
J'ai aussi repris mon soft de guidage sur fente qui m'a enfin permis de guider 2h sans voir la comète sortir de la fente !
Quelques détails dans la raie 4880 CN mais je n'ai pas les compétences pour l'identification.

La comparaison de deux nuits:
Comete sur 2 nuits
Comete sur 2 nuits

Zoom région Cn 4880:
ZOOM zone CN 4880A
ZOOM zone CN 4880A
compare_cometeZOOM.png (135.93 KiB) Viewed 6624 times

Image 300s avec Lunette chercheur (pour le fun !):
Chercheur
Chercheur
imageBrute300sLunetteChercheur.png (403.9 KiB) Viewed 6624 times

Sacrée comète, très faible pour ma config... !

Pierre
Jean-Pierre Masviel
Posts: 35
Joined: Thu Oct 06, 2011 12:54 pm

Re: Comete C2019Y4 ATLAS UVEX g1200

Post by Jean-Pierre Masviel »

Pierre, pour t'aider à indentifier les raies, tu as la page de M. Brown:

http://web.gps.caltech.edu/~mbrown/comet/

Using high-resolution spectra obtained with the Hamilton echelle spectrograph at Lick Observatory, we have constructed a catalogue of emission lines observed in comets Swift-Tuttle and Brorsen-Metcalf. The spectra cover the range between 3800 and 9900 A with a spectral resolution of ~ 42000. In the spectra, we catalogue 2997 emission lines of which we identify 2437. We find cometary lines due to H, O, C2, CN, NH2, C3, H2O+, CH, and CH+. We list 559 unidentified lines compiled from the two spectra.


Jean-Pierre
LHIRES III # 24, ALPY 600, Atik 314
http://astrosurf.com/jpmasviel/
Michel Verlinden
Posts: 191
Joined: Tue Aug 16, 2016 12:11 am

Re: Comete C2019Y4 ATLAS UVEX g1200

Post by Michel Verlinden »

Bravo Pierre, vraiment pas facile cette cible, elle n'est pas très brillante.

Une modification de la structure de l'objet est rapportée dans les ATEL. Possible amorce de désintégration amorcée depuis quelques jours.
http://www.astronomerstelegram.org/?read=13622

Image de la comète dans la nuit du 4 au 5 avril. Filtre clair. Addition des images alignées sur les étoiles.
2 queues ? 2 noyaux ? Artéfact ?
c2019y4_add_sk.jpg
Amicalement,
Michel Verlinden
Dubreuil Pierre
Posts: 202
Joined: Sat Oct 01, 2011 12:34 pm

Re: Comete C2019Y4 ATLAS UVEX g1200

Post by Dubreuil Pierre »

Merci Jean-Pierre pour l'identification. En fait la raie 3880 est large mais que tu CN !

Merci Michel, aussi je vérifierai ce soir si je vois aussi un dédoublement, donc 2 comètes !

Pierre
Robin Leadbeater
Posts: 1926
Joined: Mon Sep 26, 2011 4:41 pm
Contact:

Re: Comete C2019Y4 ATLAS UVEX g1200

Post by Robin Leadbeater »

Michel Verlinden wrote:Bravo Pierre, vraiment pas facile cette cible, elle n'est pas très brillante.

Une modification de la structure de l'objet est rapportée dans les ATEL. Possible amorce de désintégration amorcée depuis quelques jours.
http://www.astronomerstelegram.org/?read=13622

Image de la comète dans la nuit du 4 au 5 avril. Filtre clair. Addition des images alignées sur les étoiles.
2 queues ? 2 noyaux ? Artéfact ?
Nick James, (BAA comet section director) has just posted some measurements showing a small change in orbit suggesting either a break up or significant increase in outflowing material. He is also seeing a more diffuse coma
https://britastro.org/node/21355
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
David Boyd
Posts: 161
Joined: Wed Dec 11, 2013 5:50 pm

Re: Comete C2019Y4 ATLAS UVEX g1200

Post by David Boyd »

Here is a comparison of two spectra of C/2019 Y4 (ATLAS) taken with a LISA on a C11. These are integrations of 130 and 90 mins respectively. The spectrum on 26 March was taken just before the recent disruption of the comet noted by several observers, the spectrum on 6 April was taken after. Reports indicate that the event has reduced the brightness of the comet by about a magnitude and it has become more diffuse. This was apparent from the increased difficulty in guiding on the comet in the later spectrum. The later spectrum also suffers from greater noise beyond that expected just from the reduced exposure time. However, it appears that the event has not introduced any significant change in the spectral profile of the comet.

David
C2019 Y4 (ATLAS) 26 March + April 6 2020.png
C2019 Y4 (ATLAS) 26 March + April 6 2020.png (84.2 KiB) Viewed 6512 times
Dubreuil Pierre
Posts: 202
Joined: Sat Oct 01, 2011 12:34 pm

Re: Comete C2019Y4 ATLAS UVEX g1200

Post by Dubreuil Pierre »

David Boyd wrote:Here is a comparison of two spectra of C/2019 Y4 (ATLAS) taken with a LISA on a C11. These are integrations of 130 and 90 mins respectively. The spectrum on 26 March was taken just before the recent disruption of the comet noted by several observers, the spectrum on 6 April was taken after. Reports indicate that the event has reduced the brightness of the comet by about a magnitude and it has become more diffuse. This was apparent from the increased difficulty in guiding on the comet in the later spectrum. The later spectrum also suffers from greater noise beyond that expected just from the reduced exposure time. However, it appears that the event has not introduced any significant change in the spectral profile of the comet.

David
The attachment C2019 Y4 (ATLAS) 26 March + April 6 2020.png is no longer available

Belle comparaison David

Je confirme que la chute de luminosité est flagrante et il est pratiquement impossible de guider sur le noyau, ce que j'ai essayé de faire à la limite du décrochage, et pas toujours parfaitement ( passage étoiles proches du noyau).

Ci-dessous le champs du capteur de guidage posé 20s gain maxi caméra ZWO290MM. (poses 6s pendant guidage noyau)
champs Guidage 20s
champs Guidage 20s

La comète (très bruitée, posée 6x1200s)
comete  6x1200s
comete 6x1200s
Comete_3732 to 4381.png (141.48 KiB) Viewed 6466 times
zoom  3880 A
zoom 3880 A
Comete_Zoom.png (101.49 KiB) Viewed 6466 times
Pierre
Post Reply