Third Nearest WZ Sge-Type Dwarf Nova candidate ASASSN-14dx Classified on the Basis of Gaia Data Release 2. (arXiv:1811.10054v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Isogai_K/0/1/0/all/0/1">Keisuke Isogai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kato_T/0/1/0/all/0/1">Taichi Kato</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Imada_A/0/1/0/all/0/1">Akira Imada</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ohshima_T/0/1/0/all/0/1">Tomohito Ohshima</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kojiguchi_N/0/1/0/all/0/1">Naoto Kojiguchi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ohnishi_R/0/1/0/all/0/1">Ryuhei Ohnishi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hambsch_F/0/1/0/all/0/1">Franz-Josef Hambsch</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Monard_B/0/1/0/all/0/1">Berto Monard</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kiyota_S/0/1/0/all/0/1">Seiichiro Kiyota</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nishimura_H/0/1/0/all/0/1">Hideo Nishimura</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Nogami_D/0/1/0/all/0/1">Daisaku Nogami</a>

ASASSN-14dx showed an extraordinary outburst whose features are the small
outburst amplitude (~ 2.3 mag) and long duration (> 4 years). Because we found
a long observational gap of 123 d before the outburst detection, we propose
that the main outburst plateau was missed and that this outburst is just a
“fading tail” often seen after the WZ Sge-type superoutbursts. In order to
distinguish between WZ Sge and SU UMa-type dwarf novae (DNe), we investigated
Gaia DR2 statistically. We applied a logistic regression model and succeeded in
classifying by using absolute Gaia magnitudes $M_{G}$ and Gaia colors $G_{rm
BP}-G_{rm RP}$. Our new classifier also suggests that ASASSN-14dx is the best
candidate of a WZ Sge-type DN. We estimated distances from the earth of known
WZ Sge stars by using Gaia DR2 parallaxes. The result indicates that
ASASSN-14dx is the third nearest WZ Sge star (next to WZ Sge and V455 And), and
hence the object can show the third brightest WZ Sge-type superoutburst whose
maximum is $V$ = 8-9 mag.

ASASSN-14dx showed an extraordinary outburst whose features are the small
outburst amplitude (~ 2.3 mag) and long duration (> 4 years). Because we found
a long observational gap of 123 d before the outburst detection, we propose
that the main outburst plateau was missed and that this outburst is just a
“fading tail” often seen after the WZ Sge-type superoutbursts. In order to
distinguish between WZ Sge and SU UMa-type dwarf novae (DNe), we investigated
Gaia DR2 statistically. We applied a logistic regression model and succeeded in
classifying by using absolute Gaia magnitudes $M_{G}$ and Gaia colors $G_{rm
BP}-G_{rm RP}$. Our new classifier also suggests that ASASSN-14dx is the best
candidate of a WZ Sge-type DN. We estimated distances from the earth of known
WZ Sge stars by using Gaia DR2 parallaxes. The result indicates that
ASASSN-14dx is the third nearest WZ Sge star (next to WZ Sge and V455 And), and
hence the object can show the third brightest WZ Sge-type superoutburst whose
maximum is $V$ = 8-9 mag.

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