TCP J05390410+4748030: likely dwarf nova outburst (11.3 mag) in Auriga

Affiliation
Association Francaise des Observateurs d'Etoiles Variables (AFOEV)
Thu, 03/14/2019 - 17:21

TCP J05390410+4748030 (UG:)

Discovery details:
R.A. 05h39m04.10s, Decl. +47°48'03.0" (J2000.0)
2019 Mar. 14.4227 UT, 13.3 mag (CCD, unfiltered)
Discoverer: Yuji Nakamura (Kameyama, Mie, Japan)

2019 03 14.4227 UT
Yuji Nakamura, Kameyama, Mie, Japan, reports his discovery of this TCP (mag 11.3) in Aur on a CCD frame taken on 2019 Mar 14.4227 UT (limiting mag 13.0) using a 135mm F4.0 lens. The object was not shown on a frame taken on 2019 Mar 09.4284 UT (limiting mag 13.0). There is a 19.2 mag star USNO-A2.0 1350-06029095 on this position.

2019 03 14.65 UT
Gaia DR2 position end figures for the abovementioned star USNO-A2.0 1350-06029095 are 04.103s, 00.71" (equinox J2000.0, epoch 2015.5; Gmag. 19.67, parallax 3.0826 ± 0.5239 mas, distance ~0.3 kpc). Other designations are USNO-B1.0 1378-0184085, GSC2.3 NAO9008900, PSO J053904.098+474800.708, GALEX J053904.0+474800, AllWISE J053904.08+474759.9, WDJ053904.11+474800.65WDJ053904.11+474800.65. The transient is probably a dwarf nova outburst with an amplitude of about 8 magnitudes (WZ Sge type?).
*** Spectroscopy as well as multiband and time-resolved photometry are strongly recommended. ***
--- Patrick Schmeer (Saarbrücken-Bischmisheim, Germany)

Affiliation
American Association of Variable Star Observers (AAVSO)
Observation Frequency?

Hello! I've been obtaining one observation per evening. Is that what is needed, or are more frequent observations helpful? Best regards.

Mike

Affiliation
American Association of Variable Star Observers (AAVSO)
Target and Comp Error Ranges - What Accuracy is Expected?

Hello! I made a time series of the nova last night in I,B, and V. There was no clear pattern - the mags were scattered around 0.1 to 0.2 mag area.

    I analyzed the images using all the comps in my 12' x 18' FOV and just using the brightest 3 comps. The error ranges are much better - under 0.05 mags and there appears to be the start of low amplitude periodicity seen by other observers.

    I have an 8" LX200 classic and ST-402 camera. The SNR of each of my images was about 115.

    I see that the brighter comps have an error range of about 0.08 in B, 0.05 in V, and 0.13 in I. The comps with millimag errors have mags about 15 to 16, and so are too dim for my equipment.

    Is it OK to just use the three brightest comps for analysis?

    Should the error range of the target reflect be consistent with the error ranges of the comps?

    Thank you and best regards.

Mike

Affiliation
Royal Astronomical Society of Canada (RASC)
Last night's observations - mean of 12.69 in V

I observed this star for a few hours last night. It is varying at a period of about 40 minutes at an amplitude of about 0.07 mags. Plot attached.

Affiliation
American Association of Variable Star Observers (AAVSO)
Period Analysis

Period analysis with Peranso from last night's run (190320).

Affiliation
Royal Astronomical Society of Canada (RASC)
Looks good! I've changed my

Looks good! I've changed my photometry to ensemble for tonight - hopefully tighten up the scatter a bit (although full moon does not help!)

Affiliation
American Association of Variable Star Observers (AAVSO)
Time Series

Hello! 0.01 magnitude period for a time series may be too much for my setup given the integration time I would have to use. I'll continue with once nightly observations for now since others are covering this well. Best regards.

Mike