weo
Affiliation
American Association of Variable Star Observers (AAVSO)
Tue, 01/23/2024 - 19:05
AAVSO Alert Notice 847 announces an observing campaign beginning immediately on the very interesting SDOR variable PSN J12355230+2755559 (= AT 2016blu) (Com). Please see the notice for details and observing instructions.
There are threads for this campaign under the following AAVSO forums:
- Campaigns & Observation Reports: https://www.aavso.org/psn-J-12355230-2755559-2024
- Cataclysmic Variables: https://www.aavso.org/psn-J-12355230-2755559-2024-01
Please subscribe to these threads if you are participating in the campaign so you can be updated. Join in the discussion or ask questions there!
Many thanks, and Good observing,
Elizabeth O. Waagen, AAVSO HQ
My image tonight seems to show a detectable brightening? Needs confirmation.
Ken
Based on the magnitude you reported (16.776), it is very likely that it is undergoing the predicted eruption. Unfortunately, being new to this platform, I am unsure of how to view the image you took.
This target is not easy to measure due to the very small adjacent contaminant nebulosity. We should get another confirmation. The are 2 other recent observers, so hopefully they will image again soon.
I'm planning to take another image tonight if weather cooperates. I'll try to get the image to you via email?
Ken
Yes, it would be great if you send them to me via email. Thank you.
Probably a false alarm after second image 2 hours later? Really a tough target due to small contaminant nebulosity and faintness?
Should probably use a larger scope than the 12" I used (iT18) to get better resolution? I'll try again! ;-)
Ken
I have just submitted 3 days of photometry:
1/29/24 16.886R
1/31/24 16.794R
2/1/24 16.981R
Cloudy last night.
Barbara
I decided to redo my photometry after looking closer at the DSS chart. My initial photometry included this wide complex. I repeated the photometry and used an annulus that only included that portion of the star that is close to the galaxy's core. With that annulus, these are my results:
1/29/24 17.544(R) ERR 0.022
1/31/24 17.654(R) ERR 0.030
21/25 17.710(R) ERR 0.027
Barbara
/sites/default/files/users/user56530/PSN.JPG
Thanks for sharing the image. Yes, AT 2016blu is the star closer to the galaxy.
Took an image with iT72 this AM. Quite sure I have correct target now. Mag is 17.978 +-0.113 CR.
Image is shown in attached link. /sites/default/files/users/user56482/AT2016blu%20iT72%20240202.PNG
Ken
Mag 18.181R, ERR 0.055, JD 343.810
Barbara
On JD 343.71, a stack of 24 x 90sec exposure images with my 14 inch telescope reveals no star at expected position near the HII region (IC 3550)
I found an annotated SLOAN image on web page: https://cseligman.com/text/atlas/ic35a.htm which shows a close-up of the IC 3550 region (Courtney Seligman). I assume the AT2016blu is one of the two stars at the lower right of the main HII region, SE of the main HII region adjoining the main nebulosity. My stacked CCD images show no distinct stars there which I interpret as no flare-up of AT 2016 blu. Any comments?
Don Collins (CDK)
Yes, AT 2016blu is one of the two stars, the one closer to the galaxy is AT 2016blu. If AT 2016blu is very faint, then, as you said, it means it is not experiencing an eruption. However, if it is bright, then it is experiencing an eruption.
By "the galaxy" do you mean IC 3550 or the big near-by galaxy NGC 4959?
Thanks, CDK
NGC 4559
Greetings,
The "Big Galaxy" nearby this object with the long name, PSN J12355230+2755559 (= AT 2016blu), is NGC 4559. It is located in Coma Berenicis and is of Sc type.
Ahhh, the wonders of real-time editing... I'll play along... subject line "is" is now "was". Have fun, we are getting well paid for this.
Jim (DEY)
Sorry for the typo; I meant NGC 4559. Most likely, CDK also meant NGC 4559, not NGC 4959.
I also made a typo. I see from my telescope program that the "big Galaxy" is NGC 4559 (also Caldwell 36).
Star AT 2016 blu is next to IC 3550
The link below is an image of IC 3550 I've download from the web (a sloan image). I have marked a star within the IC 3550 with hatch marks. Is the marked star our target: AT 2015 blu?
https://aavso-cdk.blogspot.com/2024/02/ic-3550-hii-region-near-ngc-4559.html
Thanks,
CDK
Yes, the marked star is AT 2016blu.
Thank you. I clearly did not see it on JD 343.7.
Don (CDK)
Dear All, my photometry
PSN J12355230+27555592460347.7258832024 Feb. 07.22588 17.387 0.069 R MDJ
Image:
https://drive.google.com/file/d/1dDcnOV74C2N16HG9QIKe8O29XR9RXHgv/view?usp=drive_link
Regards.
Prof. Daniel J. Mendicini
SEV-CODE/LIADA.
Santa Fe, Argentina.