After 15 years from the first observed outburst, the NS-LMXB Transient XTE J1701-462 turned on again on September 6 (Iwakiri et al. 2022, ATel 15592). The MAXI light curve indicates that it is likely to reach the peak in luminosity within a week and its luminosity is approaching 500mCrab in the 2-10 keV band.Among its class XTE J1701-462 is a unique target: it is the only known NS to exhibit (Lin et al. 2009) all the NS-LMXB spectral substates from Cyg X-2-like Z class, up to Sco X-1-like Z, and back down to bright atoll and island atoll states during its 2006 outburst evolution. We request INTEGRAL observations of XTE J1701-462 coordinated with the approved IXPE TOO programme, foreseen on Sept. 29 and Oct. 9 2022.
The INTEGRAL (International Gamma-Ray Astrophysics Laboratory) mission, launched by the European Space Agency (ESA) on October 17, 2002, was designed to study high-energy phenomena in the universe. INTEGRAL was operating until february 2025 and it was equipped with three high-energy instruments: the Imager on Board the INTEGRAL Satellite (IBIS), the Spectrometer on INTEGRAL (SPI), and the JEM-X (Joint European Monitor for X-rays). Its Optical Monitoring Camera (OMC) provided optical V-band magnitude measurements, complementing the high-energy observations.
