We report observations of a transient source Fermi J1544-0649 from radio to γ-rays. Fermi J1544-0649 was discovered by the Fermi-LAT in May 2017. Follow-up Swift-XRT observations revealed three flaring episodes through March 2018, and the peak X-ray flux is about 10³ higher than the ROSAT all-sky survey (RASS) flux upper limit. Optical spectral measurements taken by the Magellan 6.5-m telescope and the Lick-Shane telescope both show a largely featureless spectrum, strengthening the BL Lac interpretation first proposed by Bruni et al. (2018). The optical and mid-infrared (MIR) emission goes to a higher state in 2018, when the flux in high energies goes down to a lower level. Our RATAN-600 m measurements at 4.8 GHz and 8.2 GHz do not indicate any significant radio flux variation over the monitoring seasons in 2017 and 2018, nor deviate from the archival NVSS flux level. During GeV flaring times, the spectrum is very hard (${\mathrm{\Gamma }}_{\gamma }\sim$1.7) in the GeV band and at times also very hard ((${\mathrm{\Gamma }}_{\mathrm{X}}\lesssim 2$) in the X-rays, similar to a high-synchrotron-peak (or even an extreme) BL Lac object, making Fermi J1544-0649 a good target for ground-based Cherenkov telescopes.

我们报告了从无线电到γ射线的瞬态源费米J1544-0649的观察结果。费米J1544-0649被发现˚F ERMI-LAT在五月2017年后续小号wift-XRT观测到2018年三月揭示了3个燃烧事件，峰X射线通量为10 ³比更高[R OSAT清一色天空测量（RASS）通量上限。通过采取光学光谱测量中号agellan 6.5米望远镜和大号ick-Shane望远镜都显示出基本上没有特征的光谱，从而加强了Bruni等人首先提出的BL Lac解释。（2018）。当高能通量下降到较低水平时，2018年的光学和中红外（MIR）发射将达到更高的状态。我们在4.8 GHz和8.2 GHz上进行的R ATAN-600 m测量未显示在2017年和2018年的监测季节内任何显着的无线电通量变化，也未偏离档案N VSS通量水平。在GeV爆发期间，光谱非常困难（${\mathrm{\Gamma }}_{\gamma }〜$1.7）在GeV乐队中，有时也很困难（（${\mathrm{\Gamma }}_{\mathrm{X}}\lesssim 2$）在X射线中类似于高同步加速器峰值（甚至是极端的）BL Lac物体，这使得费米J1544-0649成为地面切伦科夫望远镜的理想目标。