UZ Boo

[Gary Poyner]

More interesting VS activity for you to get your teeth into…

Japanese observer Masayuki Moriyama has reported the UGWZ type dwarf nova in outburst on August 08.531UT at magnitude 12.91C (vsnet-outburst 31039). This is the brightest outburst to be detected since March 2019. The field is getting pretty tricky in the evening sky from the UK, so any observations will be greatfully received. Please upload to the VSS DB asap.

The 2013 outburst was probably the best covered, with four rebrightenings observed after the initial outburst. The whole event lasted around a month.

UZ Boo can be found at 14 44 01.21 +22 00 54.8 (J2000.0), and charts can be plotted and configured to your telescope at the AAVSO Variable Star Plotter here

Good luck,
Gary

• This topic was modified 3 months ago by Gary Poyner.

[Jeremy Shears]

These cataclysmic variables are certainly keeping us on our toes, Gary!

[Gary Poyner]

They never stop, do they Jeremy! Thank goodness!

Gary

[Magnus Larsson]

Hi!

Managed a few observations between the clouds. Some movements around 12.3 mag in C (clear filter).

Magnus

[Dr Paul Leyland]

Still rather easy here in the deep south.

Now taking images but it looks around V=12.3. Precise measurements will be sent to the database when the data is in.

[Gary Poyner]

Thanks both.

Heavy cloud here in Birmingham, but just secured an image using SLOOH in Tenerife. A quick look at the live view matches your mid 12 estimates. I won’t get the fits file until mid morning tomorrow.

Keep going if you can.

Gary

[Dr Paul Leyland]

Gary: by “keep going” do you mean time series in a single night (like what I am currently doing for ARPS asteroidal rotational light curves) or mean making one or a few measurements per night for as long as possible?

I am hoping the latter.

[Mr Ian David Sharp]

Hi all,

Just processed 7 images from Spain overnight. Average of 12.38 in V. See attached. Data has been uploaded.

Cheers
Ian.

Attachments:

1. 

   20240808_UZ-BOO_V_PixelSkies-C11_IDS_plot_points.png
   

2. 

   20240808_UZ-BOO_V_PixelSkies-C11_IDS_plot_lines_check.png
   

[Gary Poyner]

Paul,

Whatever suits you really. The outbursts are so rare that t/s is always welcomed, but if your busy on another project then stick with that.

Gary

[Magnus Larsson]

Hi!

A series from my backyard, C11 with a QHY268m camera, clear filter. There are some odd outliers, lower magnitude, that I am in the process of trying to understand (the ref-, check, and compstars all look quite OK-ish), so maybe it will be somewhat adjusted before I submit the observations to the database. Maybe, maybe, a tendency to humps?

Magnus

Attachments:

1. 

   2024-08-09_UZ_Boo.png
   

[Jeremy Shears]

These are fairly small variations, Magnus, so it might be that superhumps haven’t started yet if the outburst is still in its early stages. In previous superoutbursts, orbital humps (~0.1 mag amp) appear first, followed by larger superhumps after ~3 days. Definitely worth following over the next nights.

[Magnus Larsson]

Hi!

After re-analyzing the images, carefully examining the images and removing some hit by wind and some other stuff, including increasing the apertures, I get a more smooth graph, and indeed, very small movements, probably mostly noise.

Magnus

Attachments:

1. 

   2024-08-09_UZ_Boo-1.png
   

[Mr Ian David Sharp]

Here are my measurements from a few minutes ago in Spain.

Average of 15 V images = 12.51

Cheers
Ian.

Attachments:

1. 

   20240810_UZ-BOO_V_PixelSkies-C11_IDS_plot_points.png
   

[Dr Paul Leyland]

Although UZ Boo is still well placed in the sky from La Palma the sky itself has been appalling and it was not worth opening the observatory between 08-09 and 08-13 inclusive. Thick Saharan dust and high winds which create turbulence and bad seeing. Even last night A 15-pixel (8.75″) radius aperture was needed to include the bloated stars and the moonlit dust made the sky background so high that a 10 minute exposure was used to get adequate SNR. Such a time would generally let me get useful results for a target fainter than V=15.

Anyway, UZ Boo was measured at V=12.35 on 2024-08-08 and 12.75 on 2024-08-14.

[Mr Ian David Sharp]

Hi all,

I managed 18 decent measurements in V last night with SNR around 150 and the average was 12.87 – see attached.

Cheers
Ian.

Attachments:

1. 

   20240816_UZ-BOO_V_Ham-Observatory-Selsey-UK_IDS_plot_points.png
   

2. 

   UZ-BOO-20240817.jpg
   

[Magnus Larsson]

Hi!

A series from my back yard yesterday (C11, QHY268m, V-filter). Now superhumps are clearly visible, somewhat asymmetrical. Observations submitted to the database and to AAVSO.

Magnus

Attachments:

1. 

   2024-08-17_UZ_Boo.png
   

[Gary Poyner]

Good work Magnus. These are the first Sh I’ve seen during this outburst. Can you continue to follow to see how they develop?

Gary

[Magnus Larsson]

Hi!

Yeah, I will! We’re actually two Swedes covering this, me and David Heinonen. It seems that it is possible to identify superhumps already the 12th, although with low amplitude (all the data is in the AAVSO database). Together with Ian’s observations, we should have good coverage, I hope 🙂

Magnus

[Mr Ian David Sharp]

Hi all,

I managed 39, 120s exposures last night from here in the South of the UK. The sky was very milky due to the Canadian wildfires, so the quality was not as I had hoped. Graph attached and data in BAA and AAVSO databases.

Cheers
Ian.

• This reply was modified 2 months, 2 weeks ago by Mr Ian David Sharp.

Attachments:

1. 

   UZ-Boo-20240818.jpg
   

[Jeremy Shears]

Good to see this coverage of UZ Boo and especially to see the appearance of SH’s. Hopefully these will grow.
The sky here last evening was dreadful: I could only see Vega, Altair and a very coppery Moon.

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