General information
NuSTAR Transient 260828 is described in the provided circulars as a fast X-ray transient detected by NuSTAR, followed up optically from Chile. Both reported follow-up observations found no new source within the NuSTAR localization.
Wavelength coverage
- X-ray: The event is stated to have been detected by NuSTAR, but no X-ray flux, duration, spectrum, or position details are provided in the supplied circulars.
- Optical: LCO 1m/SINISTRO observed in SDSS r and z bands and reported 3-sigma nondetections of r > 22.22 at ~3.59 days and z > 21.31 at ~3.61 days after detection.
- Optical: SOAR/Goodman observed in SDSS r band and reported a 3-sigma nondetection of r > 22.25 at ~3.64 days after detection, consistent with the LCO r-band limit.
No observations are mentioned in gamma-ray, UV, infrared, radio, gravitational-wave, or neutrino bands.
Lightcurve and spectrum
- LCO image subtraction against archival Pan-STARRS stacks found no new source in r or z within the NuSTAR uncertainty region.
- SOAR image subtraction using an archival Pan-STARRS1 reference found no new source within the NuSTAR localization.
- The reported optical limits are AB magnitudes and are not corrected for Galactic extinction; LCO notes A_V = 1.74 mag.
Redshift
What’s special vs typical