V538 Mon brightening
Moriyama-san and Kojima-san have detected brightening of this unusual object.
YYYYMMDD(UT) mag observer 20220302.2048 14.930zg (Zwicky Transient Facility (Masci et al., 2019)) 20220302.2048 15.016zg (Zwicky Transient Facility Lasair (Masci+ 2019)) 20220324.5845 144C (Masayuki Moriyama) 20220402.1521 14.443zr (Zwicky Transient Facility (Masci et al., 2019)) 20220403.5566 142V (Masayuki Moriyama) 20220405.1542 14.494zg (Zwicky Transient Facility (Masci et al., 2019)) 20220405.2061 14.233zr (Zwicky Transient Facility (Masci et al., 2019)) 20220407.1549 14.051zr (Zwicky Transient Facility (Masci et al., 2019)) 20220407.2037 14.356zg (Zwicky Transient Facility (Masci et al., 2019)) 20220409.1595 14.613zg (Zwicky Transient Facility (Masci et al., 2019)) 20220409.1971 14.493zr (Zwicky Transient Facility (Masci et al., 2019)) 20220413.1624 14.598zr (Zwicky Transient Facility (Masci et al., 2019)) 20220413.1757 14.790zg (Zwicky Transient Facility (Masci et al., 2019)) 20220416.1616 14.753zg (Zwicky Transient Facility (Masci et al., 2019)) 20220416.1998 14.614zr (Zwicky Transient Facility (Masci et al., 2019)) 20220418.1814 14.630zg (Zwicky Transient Facility (Masci et al., 2019)) 20220418.5398 144C (Masayuki Moriyama)
20220927.8218 123C (Masayuki Moriyama) 20221017.8553 122C (Masayuki Moriyama) 20221029.7559 117c (Tadashi Kojima) 20221030.6906 123C (Masayuki Moriyama)
Subject: [vsnet-chat 8618] V538 Mon (2021 July 1)
https://www.aavso.org/vsx/index.php?view=detail.top&oid=19366
Type: AM: in unlikely. Too bright.
Subject: [vsnet-chat 8161] V538 Mon: stange variable (2018 Sep. 6)
V538 Mon: stange variable
ASAS-SN data (combined light): https://asas-sn.osu.edu/light_curves/8fec5b82-fa72-4fad-a016-2e1fb02d25bd
It's not EA: (as in GCVS). The object is too faint for a typical EXOR.
062416.229 +053640.05 (2000.0) Gaia_DR2_3323819257020229888 plx=1.396(0.053) dismod=9.3 pmra=-2.116(0.066) pmdec=0.626(0.058) G=13.822 BP=13.742 RP=13.355
I suspect that the object may be an Z Cam/NL object which spent most of 2017 in low state (currently brighter again).
Spectroscopic observations will be interesting.
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The type is currently given as UGZ//IW: | NL: in VSX. The nature of this object is not yet understood.
062416.2 +053640 (2000.0) Gaia19dqa vtype=YSO TNSid=AT2019oap Comment=know_YSO_(EXOR)_V0538_Mon_brightens_by_2.5_mag
062416.229 +053640.05 (2000.0) Gaia_EDR3_3323819257020229888 plx=1.461(0.024) dismod=9.2 pmra=-2.119(0.024) pmdec=0.722(0.023) G=13.909 BP=13.894 RP=13.598
Could be a YSO considering the possible association with AKARI-IRC J0624162+053638, but the object is too blue in the optical.