AT 2000ch (LMi) campaign - Alert Notice 853

Affiliation
American Association of Variable Star Observers (AAVSO)
Tue, 02/20/2024 - 22:39

AAVSO Alert Notice 853 announces an observing campaign beginning immediately on the SDOR variable AT 2000ch (LMi). 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/at-2000-ch-2024
- Cataclysmic Variables: https://www.aavso.org/at-2000-ch-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

Affiliation
American Association of Variable Star Observers (AAVSO)
Data from last night

We used the Madrona Peak Obs 0.6m Ritchey to get a 15min summed Rc image of this star last night.  Submitted our measurement of Rc=19.399 (0.094).  Will have to sum more 5min images to go deeper next time skies clear.  This one is a challenge.

-Walt Cooney (cwt)

Affiliation
American Association of Variable Star Observers (AAVSO)
AT 2000ch (Feb 24)

Looks like I am the other observer and I agree-- this one is definitely faint.  I have it at mag 19.447 on Feb 24-- 24 minutes total using the 0.9-meter SARA at Kitt Peak.

Tom (rth)

Affiliation
American Association of Variable Star Observers (AAVSO)
May 26th 2024 SN 2000ch not detected at all

well I tried. Celestron C14 Edge HD 10 minute subs in R for several hours. Moonlit sky, unable to detect it at all..Following is a stacked image..My Observatory can go down to about 20.5 Mag on good nights Last night was NOT a good night..Bright Urban Los Angeles Sky. I tried posting a picture here but it didn't work

Affiliation
American Association of Variable Star Observers (AAVSO)
galaxy glow

My Madrona Peak .6m images have been one hour total integration time with an Rc filter.  The 11 measurements so far have ranged from 19.2 to 20.1, but those numbers are biased to the bright side.  I'm keeping the measurement aperture small to eliminate at least some of the galaxy glow, but I'm not attempting to subtract the underlying glow from the aperture.   Hopefully the measurements are still useful as an indicator of whether the star is in outburst or not.

-Walt