The Helping Hand is a dark cloud in the constellation of Cassiopeia. It consists of three separate dark clouds known as LDN 1355, LDN 1357, and LDN 1358. Their distance is not known accurately, with estimates ranging between 490 and 815 light-years.
These dust-rich clouds are associated with the Cepheus flare, a molecular cloud and a star-forming region. Dark clouds are areas of great interest since they are regions associated with star formation and very young stars.
The region is “contaminated” by small reflection nebulae. The brightest star in the region is an eclipsing variable star known as RZ Cas. The binary consists of an A3V-type and a K0IV-type star with an orbital period of around 1.2 days. The primary component has a mass of nearly two solar masses, and its nearby companion has a mass of 0.7 solar masses. The binary is responsible for powering the faint reflection nebula VdB 7.
The other reflection nebula is VdB9. It is powered by SU Cas, a Cepheid variable (F5 Ib/II-F7 Ib/II type), with a pulsation period of around two days. Below this small reflection nebula, another faint but much larger reflection nebula is located. This is known as LBN 643.
Image: Composite optical image of the Helping Hand Nebula taken with a small amateur telescope. It was created using broadband filters (RGB). LDN 1358 is on the top right, while as we move towards the left and below, LDN 1355 and LDN 1357 are located. VbB9 is located just below the two dark clouds, with LDN 643 extending below it. Finally, VbB 7 is towards the bottom right section of the image next to the brightest star there, RZ Cas.
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