Blanco 1

Blanco 1 (ζ Sculptoris cluster) is a nearby open cluster of stars located around 850 light years away from the Sun in the southern constellation of Sculptor near the star ζ Sculptoris. It was discovered by Puerto Rican astronomer Víctor Manuel Blanco in 1949,^[1] who noticed an unusually high proportion of A-type stars in an area spanning 1.5°.^[2] This cluster is relatively young, with an age of about 100–150 million years. It is positioned at a high galactic latitude of b = –79.3° and is located some 780 ly (240 pc) below the galactic plane.

Blanco 1 contains approximately 300 stars, around 170 of these being brighter than magnitude +12,^[3] the brightest of which is HD 225187, a 7th-magnitude B8V star. It has a cross-sectional magnitudal density of about 30 per square parsec: less than half that of the Pleiades cluster. Of the confirmed members, eight have been found to radiate an excess of infrared energy, indicating that they host orbiting debris disks.^[4] Roughly half the stars in the cluster are members of binary star systems; six of the member stars are confirmed spectroscopic binaries.^[5] A system known as NGTS J0002-29 is a triple system that contains one of only a few well-characterised eclipsing binaries with two red dwarfs: they orbit each other with a period of 1.098 days.^[6] There are also some 30–40 brown dwarf members.^[1]