Triangulum

RD1 or 0140+326 RD1 is a distant galaxy, it once held the title of most distant galaxy known. RD1 was discovered in March 1998, and is at z = 5.34, and was the first object found to exceed redshift 5. It bested the previous recordholders, a pair of galaxies at z=4.92 lensed by the galaxy cluster CL 1358+62 (CL 1358+62 G1 & CL 1358+62 G2). It was the most distant object known to mankind for a few months in 1998, until BR1202-0725 LAE was discovered at z = 5.64.

HAT-P-38, formally named Horna, is a star located in the northern constellation Triangulum. It has an apparent magnitude of 12.51, making it readily visible in amateur telescopes but not to the naked eye. The object is located relatively far at a distance of 821 light-years based on Gaia DR3 parallax measurements, but it is drifting closer with a spectroscopic radial velocity of .

M33-013406.63, also known as B416 or UIT301, is a O-type blue evolved supergiant star in the constellation of Triangulum. It is located within the Triangulum Galaxy, which is approximately 2,380,000–3,070,000 light years away from Earth.