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NGC 2004 #115 is a recently identified black hole (BH) candidate in the LargeMagellanic Cloud (LMC) containing a B star orbiting an unseen companion in a2.9 day orbit and Be star tertiary. We show that the unseen companion is not a$25\,M_{\odot}$ BH, but a $(2-3)\,M_{\odot}$ luminous star. Analyzing the OGLEand MACHO light curves of the system, we detect ellipsoidal variability withamplitude 10 times larger than would be expected if the companion were a$25\,M_{\odot}$ BH, ruling out the low inclination required for a massivecompanion. The light curve also shows a clear reflection effect that iswell-modeled with a $2.5\,M_{\odot}$ main-sequence secondary, ruling out alower-mass BH or neutron star companion. We consider and reject models in whichthe system is a binary containing a stripped star orbiting the Be star: only atriple model with an outer Be star can explain both the observed light curveand radial velocities. Our results imply that the B star, whose slow projectedrotation velocity and presumed tidal synchronization were interpreted asevidence for a low inclination (and thus a high companion mass), is far frombeing tidally synchronized: despite being in a 2.9 day orbit that is fully ornearly circularized ($e < 0.04$), its surface rotation period appears to be atleast 20 days. We offer cautionary notes on the interpretation of dormant BHcandidates in binaries.

NGC 2004 #115: a black hole imposter containing three luminous stars