A strange creature lurks in the depths of the Serpens Nebula, 1300 light years away. Here, where stars are born amid swirling dust and gas, lies a young star HBC 672, also known as bat shadow. This star is famous for having what appear to be shady wings, and now scientists using the Hubble space telescope have discovered something strange: these wings seem to flutter.
This picture shows only the function that bears the nickname bat shadow. It is the shadow of a protoplanetary disk orbiting the star in the center of the picture. NASA, ESA, K. Pontoppidan
Astronomers first observed the shadow of HBC 672 in 2018 and suspected that the star is surrounded by a planet disk that, although not directly observed, casts a shadow on a cloud behind it. And now when you see this shadow, you think it could be caused by a planet that goes through the disc and warps it, which in turn warps the shadow.
"You have a star that is surrounded by a disk, and the disk is not like Saturn rings – it is not flat. It is inflated," said lead author Klaus Pontoppidan in a statement. "And that means the light of the star if it goes straight up it can go straight up – nothing will block it. "But if it tries to walk along the plane of the disc it won't come out and cast a shadow."
This image shows the serpian nebula from the perspective of the HAWK-I instrument installed on the Very Large Telescope of the European Southern Observatory. The filters used by HAWK-I to create this image cover wavelengths that are similar to the filters used by Hubble. ESO
Although the disc itself is too small and far to be seen by Hubble, the researchers believe it is saddle-shaped, which would explain the shadow's apparent movement. "If there were only a simple dent in the window, we would expect both sides of the shadow to tilt in opposite directions, like airplane wings during a turn," said team member Colette Salyk in the statement.
The shadow is absolutely massive and is 200 times the diameter of our solar system. In fact, it is so large that it takes about 45 days for the star's light to reach its edge.
The results are published in the Astrophysical Journal.