Galaxy in the constellation Leo
NGC 3947 is a barred spiral galaxy in the constellation of Leo . Its velocity with respect to the cosmic microwave background is 6528 ± 23 km/s, which corresponds to a Hubble distance of 314.0 ± 22.0 Mly (96.28 ± 6.75 Mpc ).[ 1] In addition, three non redshift measurements give a distance of 284.67 ± 12.90 Mly (87.28 ± 3.956 Mpc).[ 2] It was discovered by German-British astronomer William Herschel on 26 April 1785.[ 3]
Four supernovae have been observed in NGC 3947. SN 1972C (type unknown, mag. 16)[ 4] was discovered by Charles Kowal on 18 January 1972. The other three supernovae are: SN 2001P (type Ia , mag. 17.5),[ 5] SN 2006aa (type IIn , mag. 18.1),[ 6] and SN 2013G (type Ia, mag. 16).[ 7]
Some galaxies of the NGC 3842 group. NGC 3947 is part of the 16 member NGC 3842 group, named after the brightest galaxy in the group. The other galaxy members are: NGC 3805 , NGC 3837 , NGC 3842 , NGC 3860 , NGC 3862 , NGC 3883 , NGC 3884 , NGC 3919, NGC 3929, NGC 3937 , NGC 3940, NGC 3954 , UGC 6583, UGC 6697 , and UGC 6725.[ 8]
Like many of the neighboring galaxies, NGC 3947 and the galaxies in the NGC 3842 group are part of the Leo galaxy cluster (also known as Abell 1367).