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LEDA 74886

Dwarf galaxy in the constellation Eridanus with a rectangular shape

LEDA 74886
False color image of galaxy LEDA 74886, taken by the Subaru Telescope. The contrast of this image has been adjusted to highlight the internal disk/bar like structure.
Observation data (J2000 epoch)
Constellation	Eridanus
Right ascension	03h40m 43.233s[1]
Declination	−18° 38′ 43.10″[1]
Distance	70,000 kly (21,000 kpc) h−1 0.73
Grouporcluster	NGC 1407[2]
Characteristics
Type	S0 [3]
Mass	1×109 M☉
Other designations
2MASX J03404323-1838431, 6dFGS gJ034043.2-183843[1]

LEDA 74886, also known by its 2MASX designation 2MASX J03404323-1838431, and sometimes known as the Emerald-cut Galaxy,^[4] is a dwarf galaxy with a rare rectangular shape.^[2] It is located at a distance of about 70,000,000 light-years (21 Mpc) in the Eridanus constellation.^[5] The galaxy was detected in a wide field of view image taken by the Subaru Telescope using the Subaru Prime Focus Camera (Suprime-Cam).^[6][7] Using the Keck Telescope, a thin disc with a side on orientation was confirmed to be lurking at the center of LEDA 74886, and spinning at a speed of 33 km/s at the orbital radius of half a kpc.^[2] LEDA 74886 has a mass of around 10⁹ M_☉ (Compared to the Milky Way's mass of about 10¹² M_☉).

LEDA 74886 is located in the celestial sphere at a right ascension (${\displaystyle \alpha }$) of 03^h40^m 43.2^s, and a declination (${\displaystyle \delta }$) of −18° 38′ 43″ (J2000). It is located within the Galactic coronaofNGC 1407, a massive spherical galaxy which is located approximately 163,000 ly (50 kpc) to the northwest of LEDA 74886.^[2]

• SDSS J074018.17+282756.3 is a spiral galaxy with arms that have a somewhat squarish-looking interior, but is distinct from LEDA 74886, because LEDA 74886 has no apparent spiral structure and a boxy like exterior form.^[2]
• Sextans A, a member of the local group, has a box like form due to its expanding shell of young blue stars, but it has a much lower mass and density, and includes a central disc which LEDA 74886 does not include.^[2]
• NGC 4488