Two‐dimensional spectra for 2148.130358 (J215031.8−053504). At top is the coadded cosmic‐ray–cleaned, two‐dimensional spectrum of the object from one mask, and below that are the two raw two‐dimensional spectra. Blue wavelengths are at left, and red at right, and strong night‐sky lines at 5577 and 5892 Å are visible. Also visible are parts of the two‐dimensional spectra of neighboring slits above and below the object’s two‐dimensional spectra. The discrepant line is between the 5892 and 6300 Å night‐sky lines, marked by two line segments bracketing the coadded two‐dimensional spectrum. It is the only emission line in this spectrum.