We recently inferred that the galaxy NGC1052–DF2 has little or no dark matter and a rich system of unusual globular clusters .
We assumed that the galaxy is a satellite of the luminous elliptical galaxy NGC1052 at \approx 20 Mpc , on the basis of its surface brightness fluctuations ( SBF ) distance of 19.0 \pm 1.7 Mpc , its radial velocity of \approx 1800 km/s , and its projected position .
Here we analyze the color-magnitude diagram ( CMD ) of NGC1052–DF2 , following the suggestion by Trujillo et al .
( 2018 ) that the tip of the red giant branch ( TRGB ) can be detected in currently available HST data and the galaxy is at \sim 13 Mpc .
Using fully populated galaxy models we show that the CMD is strongly influenced by blends .
These blends produce a “ phantom ” TRGB \sim 2 times brighter than the true TRGB , which can lead to erroneous distance estimates \sim 1.4 times smaller than the actual distance .
We compare NGC1052–DF2 to model images as well as other galaxies in our HST sample , and show that the large population of unblended RGB stars expected for distances of \sim 13 Mpc is not detected .
We also provide a new distance measurement to NGC1052–DF2 that is free of calibration uncertainties , by anchoring it to a satellite of the megamaser host galaxy NGC4258 .
From a megamaser-TRGB-SBF distance ladder we obtain D = 18.7 \pm 1.7 Mpc , consistent with our previous measurement and with the distance to the elliptical galaxy NGC1052 .