                        Astronomy Picture of the Day

    Discover the cosmos! Each day a different image or photograph of our
      fascinating universe is featured, along with a brief explanation
                    written by a professional astronomer.

                              2025 September 3
   A nebula is shown that appears roughly the shape of Africa. The complex
    radio image shows rings and jets. Please see the explanation for more
                            detailed information.

                     Cir X-1: Jets in the Africa Nebula
   Image Credit: J. English (U. Manitoba) & K. Gasealahwe (U. Cape Town),
      SARAO, MeerKAT, ThunderKAT; Science: K. Gasealahwe, K. Savard (U.
                Oxford) et al.; Text: J. English & K. Savard

   Explanation: How soon do jets form when a supernova gives birth to a
   neutron star? The Africa Nebula provides clues. This supernova remnant
   surrounds Circinus X-1, an X-ray emitting neutron star and the
   companion star it orbits. The image, from the ThunderKAT collaboration
   on the MeerKAT radio telescope situated in South Africa, shows the
   bright core-and-lobe structure of Cir X-1’s currently active jets
   inside the nebula. A mere 4600 years old, Cir X-1 could be the "Little
   Sister" of microquasar SS 433*. However, the newly discovered bubble
   exiting from a ring-like hole in the upper right of the nebula, along
   with a ring to the bottom left, demonstrate that other jets previously
   existed. Computer simulations indicate those jets formed within 100
   years of the explosion and lasted up to 1000 years. Surprisingly, to
   create the observed bubble, the jets need to be more powerful than
   young neutron stars were previously thought to produce.

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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Amber Straughn Specific rights apply.
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