Outters 4 (Ou4), also known as the Giant Squid Nebula, is a very faint planetary nebula in the constellation Cepheus, discovered only in June 2011 by amateur astronomer Nicolas Outters. Ou4 appears to be completely surrounded by the reddish hydrogen emission region Sh2-129, but its true distance and nature have been difficult to determine. A recent investigation suggests that Ou4 is actually located within Sh2-129. If so, Ou4 would represent a spectacular outflow generated by HR8119, a triple system of hot, massive stars that can be observed near the nebula's center and would have a physical diameter of nearly 50 light-years.
Sh2-129 is an extensive emission nebula visible in the constellation Cepheus, located on the southern edge of the constellation, northwest of the large nebulous complex IC 1396. This nebula has a very pronounced arc shape, almost a large ring; due to its shape, it is sometimes nicknamed the Flying Bat Nebula. Despite its size, it appears rather faint, with the densest and most visible part coinciding with its eastern side. Its distance has been estimated at around 1300 light-years, placing it a short distance from the edge of the Gouldian Belt.
Outters 4 (Ou4), also known as the Giant Squid Nebula, is a very faint planetary nebula in the constellation Cepheus, discovered only in June 2011 by amateur astronomer Nicolas Outters. Ou4 appears to be completely surrounded by the reddish hydrogen emission region Sh2-129, but its true distance and nature have been difficult to determine. A recent investigation suggests that Ou4 is actually located within Sh2-129. If so, Ou4 would represent a spectacular outflow generated by HR8119, a triple system of hot, massive stars that can be observed near the nebula's center and would have a physical diameter of nearly 50 light-years.
Sh2-129 is an extensive emission nebula visible in the constellation Cepheus, located on the southern edge of the constellation, northwest of the large nebulous complex IC 1396.
This nebula has a very pronounced arc shape, almost a large ring; due to its shape, it is sometimes nicknamed the Flying Bat Nebula. Despite its size, it appears rather faint, with the densest and most visible part coinciding with its eastern side. Its distance has been estimated at around 1300 light-years, placing it a short distance from the edge of the Gouldian Belt.