NGC 5273

NGC 5273 is a lenticular galaxy located 54 million light-years^[4] away in the northern constellation of Canes Venatici. This galaxy was discovered by William Herschel on May 1, 1785.^[8] It is positioned 1+1⁄4° to the southeast of the star 25 Canum Venaticorum.^[5]

NGC 5273
Sloan Digital Sky Survey image of NGC 5273
Observation data (J2000 epoch)
Right ascension	13h 42m 08.380s[1]
Declination	+35° 39′ 15.47″[1]
Redshift	0.00362[2]
Distance	54.1 ± 6.8 Mly (16.6 ± 2.1 Mpc)[3][4]
Apparent magnitude (V)	11.6[5] 13.12[6]
Apparent magnitude (B)	14.01[6]
Characteristics
Type	SA0(s)[4]
Apparent size (V)	2.8′ × 2.4′[5]
Other designations
NGC 5273, UGC 8675, PGC 48521[7]

The morphological classification of this galaxy is SA0(s),^[4] indicating it is lenticular in form. It displays a faint, unbarred spiral structure within a generally elliptical profile.^[9] NGC 5273 is classified as a type 1.5 Seyfert galaxy, with the X-ray emission from its active galactic nucleus undergoing significant absorption.^[10] However, data collected between the year 2000 and 2022 suggest this is a changing–look Seyfert, with the type ranging from 1 to 1.8/1.9.^[11] The activity level shows strong variability, allowing reverberation mapping of the supermassive black hole at the core. This object has an estimated mass of (4.7±1.6)×10⁶ M_☉.^[9]