MN Dra - In-the-Gap Dwarf Nova With Negative Superhumps

The multi-site photometric observations of MN Dra were made over 77 nights in August-November, 2009. The total exposure was 433 hours. During this time the binary underwent two superoutbursts and five normal outbursts. During the course of first superoutburst period of positive superhumps decreased with extremely large $\dot P = -1.5 \times 1.0^{-4}$ for SU UMa-like dwarf novae, confirming known behavior of MN Dra [1]. Between the superoutbursts MN Dra displayed negative superhumps. Their period changed cyclically around 0.096-day value.Comment: 17TH European White Dwarf Workshop. AIP Conference Proceedings, Volume 1273, pp. 320-323 (2010

OT J002656.6+284933 (CSS101212:002657+284933): An SU UMa-Type Dwarf Nova with Longest Superhump Period

We observed the 2016 outburst of OT J002656.6+284933 (CSS101212:002657+284933) and found that it has the longest recorded [0.13225(1) d in average] superhumps among SU UMa-type dwarf novae. The object is the third known SU UMa-type dwarf nova above the period gap. The outburst, however, was unlike ordinary long-period SU UMa-type dwarf novae in that it showed two post-outburst rebrightenings. It showed superhump evolution similar to short-period SU UMa-type dwarf novae. We could constrain the mass ratio to less than 0.15 (most likely between 0.10 and 0.15) by using superhump periods in the early and post-superoutburst stages. These results suggest the possibility that OT J002656.6+284933 has an anomalously undermassive secondary and it should have passed a different evolutionary track from the standard one.Comment: 6 pages, 3 figures, accepted for publication in PASJ (Letters), Note added in proof has been added. Supplementary Information (si.pdf) is available in the source fil

Field camera unit of the WSO-UV mission

The main instrument of the space mission "Spectr-UF" (World Space Observatory-Ultraviolet) is a large space telescope to work in the UV wavelength domain (115 - 310 nm). The WSO-UV telescope feeds in its focal plane two main instruments: unit of spectrographs WUVS, and field camera unit FCU, as well as Fine Guidance System (FGS). The imaging instrument FCU onboard WSO-UV will be the first UV camera to be flown to a geosynchronous orbit. Here we provide a brief description on updated FCU instrument and its current status