tokens: on pauses in X-ray bursts studied with RXTE , suggest that there is no link between the detection of double-peaked profiles and the detection of a pause during the rise. However, our interpretation would be incorrect if the pauses are short and weak manifestations of a peak in the X-ray burst profile, meaning that the X-ray burst in SAX J1808.4–3658 can be considered a triple-peaked X-ray burst, and B1 in MAXI J1807 can be considered a double-peaked burst. in’t Zand et al. ( 2003 ) reported on an unusual Type-I X-ray burst from GRS 1747-312 2 observed with RXTE whilst the system was apparently in quiescence. The 2–10 keV light curve profile exhibits a pause-like feature in the rise of the X-ray burst, while the full 2–60 keV light curve did not show a pause. The pause in the 2–10 keV light curve is considerably longer than those seen in S1 and B1 ( ∼20 s), and, judging from Fig. 2 a of in’t Zand et al. ( 2003 ), the pause occurs at roughly 70 per cent of the peak count rate. The X-ray burst also had an unusually strong PRE that was not at the start of the X-ray burst, as is expected. It is unclear whether this is a longer manifestation of the pause phenomena we see in B1 and S1, but it shows that the presence of pause-like features can depend on the energy band used. Independently of whether the pauses are related to the multipeaked phenomena discussed above, our results, together with those presented by Bult et al. ( 2019 ), show that short pauses in the rise of X-ray burst light curves occur in at least two sources, suggesting that these types of pauses might be present in the X-ray light curves of Type-I bursts from other NS-LMXBs. We only know of two sources (the accreting millisecond X-ray pulsar SAX J1808.4–3658 and MAXI J1807), each with one reported X-ray burst with a clear pause during the rise. This small sample size prevents us from a detailed study on the relation between pauses and X-ray burst characteristics/properties, and naturally it is unclear whether the pauses seen in B1 and S1 are caused by the same mechanism. However, under the assumption that we are seeing manifestations of the same phenomena in B1 and S1, even with a sample of two we can conclude that pauses in the X-ray bursts are possible in both pulsating and non-pulsating systems, suggesting that the strength of the magnetic field might not play an important role, unless the lack of pulsations in MAXI J1807 is due to an alignment between rotation and magnetic axes (Lamb et al. 2009a , b ). In addition, the occurrence of the pause does not appear to depend on the composition of the burning material either, or whether the X-ray burst reaches PRE. To our knowledge, standard X-ray burst models do not predict pauses in the X-ray burst rise. However, we note that Keek, Heger in’t Zand ( 2012 ) finds X-ray bursts with pauses in their rise when modelling X-ray bursts that occur shortly after a superburst. In the hot, He-rich atmospheres following a superburst, X-ray bursts
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