Scroll Down  to

KOI's (Blue)  or
K2 Objects (Green)

Exoplanet-Science.com

The plotted Corrected Flux vs. Time data (converted from NASA's K2 raw data by A. Vanderburg) were accessed by starting with his website https://www.cfa.harvard.edu/~avanderb/k2.html; LC data used.

Orbital period (from expanded baseline): 0.1827 ± 0.0149 days.

Outburst intervals (from quartic-fit-models, derivative-zero): 33.5102 ± 0.0117 days.
Outburst intervals (from half-maximum onset outburst times): 34.1620 ± 0.7153 days.


Relative energies (areas*) of the three (K2C1) observed outbursts: 5.4 : 1.0 : 1.5.


K2 Data Search & Retrieval (http://archive.stsci.edu/k2/data_search/search.php):
RA: 176.338185, DE: -4.434936
RA: 11 45 21.164, DE: -04 26 05.77
Other IDs: 2MASS J11452115-0426055; UCAC 428-055238.

SIMBAD (http://simbad.harvard.edu/simbad):
RA: 176.338167, DE: -4.434889
RA: 11 45 21.16, DE: -04 26 05.6
Object designation: "Dwarf Nova", TW Vir.
Orbital period: 0.18267 days.
Outburst interval: 32 days.
Distance: 460 pc.
Maximum magnitude: 11.50.
Minimum magnitude: 17.50.

*Related to approximate areas (flux • days) = summed areas of narrow trapezoids.

References:
SIMBAD (http://simbad.harvard.edu/simbad);
-- AAVSO International Variable Star Index VSX (Watson+, 2006-2014);
-- General Catalogue of Variable Stars (Samus+ 2007-2013);
-- 2MASS photometry of cataclysmic variables (Ak+, 2008).
E. Weisstein, http://scienceworld.wolfram.com/astronomy/DwarfNova.html
-- Dwarf Nova characteristics:
outburst intervals: quasi-periodic;
quasi-periods: days to decades;
outburst durations: typically from 2 to 20 days;
potential causes of outbursts: release of gravitational energy, due to instability in the accretion disk, or by a sudden mass-transfers through the disk.
-- "SU Uma" Subtype characteristic: occasional "super" outbursts with durations ~ 5 times a normal outburst.


Note:
Guidance along these lines by Andrew Vanderburg is gratefully acknowledged.

1 Mar 2015; updated 3 Mar 2015.
                              Kepler K2-C1 EPIC-201185922: Dwarf Nova

Discussion:
The literature (summarized within SIMBAD) indicates this object is a Dwarf Nova.  Moreover, it is probably an "SU UMa" subtype (see definitions and website reference below).


A comparison plot of Raw Flux Data and Arclength (telescope pointing) vs. Time showed that the fine structure most noticeable on the 1st (largest) outburst was due to pointing drifts and required corrections (see note below).