LS V +44 17 continues to rise beyond 2 Crab

ATel #15880; David M. Palmer (LANL), on behalf of the Swift/BAT team
on 31 Jan 2023; 01:34 UT
Credential Certification: David M. Palmer (palmer@lanl.gov)

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The current giant outburst of the Be/X-ray binary pulsar LS V +44 17 (also known as RX J0440.9+4431) is continuing with a steady climb to above 2 Crabs of flux as measured by Swift/BAT transient monitor analysis (15-50 keV) and other instruments.

The current outburst was originally reported from MAXI/GSC in ATel #15835 (Nakajima et al.). The BAT monitor shows that the outburst began with an initial peak and decline (starting 24-Dec-2022; peaking 4-Jan at 0.572+/-0.044 Crab; reaching a minimum on 13-Jan) followed by a rebrightening (ATel #15868, Pal et al.) with a nearly linear rise to 2.18+/-0.08 Crab as of 29-Jan. There is no evidence of a peak or plateau being reached.

All BAT monitor fluxes are reported here in Crab units using a conversion of 0.220 ct/cm^2/s over a 15-50 keV instrumental energy range, using data from the BAT monitor page (Krimm et al., 2013, ApJSS 209,14).

This is consistent with the lightcurves seen by other instruments such as MAXI and Fermi/GBM.

BAT transient monitor for this source