This list does not include near-parabolic comets of which many are known to be currently more than 100 AU (15 billion km) from the Sun, but are currently too far away to be observed by telescope. Trans-Neptunian objects are typically announced publicly months or years after their discovery, so as to make sure the orbit is correct before announcing it. Due to their greater distance from the Sun and slow movement across the sky, trans-Neptunian objects with observation arcs less than several years often have poorly constrained orbits. Particularly distant objects take several years of observations to establish a crude orbit solution before being announced. For instance, the most distant known trans-Neptunian object 2018 AG 37 was discovered by Scott Sheppard in January 2018 but was announced three years later in February 2021.