New images reveal magnetic fields in the Horsehead Nebula

Located at the East Asia Observatory (EAO) near Maunakea Peak, Hawaii, the James Clerk Maxwell Telescope (JCMT) is the world’s largest telescope designed to operate exclusively in submillimeter wavelengths. In 2018, Molokai High School graduate Mallory Jo was granted time with JCMT under the Maunakea Scholars Program. With the help of EAO astronomer Dr. Harriet Parsons, Go obtained unique images of the Horsehead Nebula in polarized light, which revealed the nebula’s magnetic fields.

Gu (now a graduate student at Brown University) submitted the photos as part of a science fair representing Molokai High School. A year later, these observations were used by a team of astronomers from the Korea Astronomy and Aerospace Institute (KASI), the University of Science and Technology (UST), and University College London (UCL) to perform a quantitative analysis of the force. And the role of magnetic fields in the region. The paper describing the observations and analyses, “Magnetic Fields in the Horsehead Nebula” recently appeared in The Astronomical Journal.

The observations taken in 2018 were taken using the JCMT’s POL-2 instrument, a linear polarimeter that acquires polarimetry data with the help of the SCUBA-2 instrument. Together, these instruments measure how magnetic fields in space affect the alignment of interstellar dust.

As Dr. Parsons explained in an EAO press release, “You can think of the POL-2 as a pair of polarized sunglasses sitting in front of a telescope. In Hawaii, many of us are used to wearing polarized sunglasses—they help us see better by reducing glare—but in The telescope, by rotating the polarizing lenses, analyzes the brightness of the light being observed and infers whether it is under the influence of magnetic fields.With such instruments, astronomers can look at clouds of gas and dust—regions both within our galaxy or beyond—and expand their understanding what constitutes it.”

Astronomers from KASI, UST, and UCL obtained additional data using JCMT’s other operational tools—the Heterochromatic Array Receiver Program (HARP) and Autocorrelation Imaging Spectroscopic System (ACSIS)—to measure the region’s brightness and intensity. The HARP instrument revealed additional spectroline data that showed the presence of a form of carbon monoxide containing oxygen-18(C).¹⁸O), a stable isotope of oxygen thought to originate in molecular clouds.

UCLA astronomer Dr. Kate Patel, one of the study’s co-authors, said, “The data is impressive and what they tell us is even more impressive. I’m delighted that Mallory gave us the opportunity to work on such a beautiful and iconic region of the sky – and what we found helps us “Understanding why the Horsehead Nebula has a shape. These observations tell the story of two dense regions hidden in the Horsehead. We see ridges of warm gas and dust – the Horsehead and Mane – interacting with ultraviolet photons from nearby bright young stars.”

The JCMT instruments allowed the team to observe the interaction between the nebula’s “head” and “mane” and the nearby one young stars– which appears to have had a marked effect on the nebula’s magnetic field. The team hypothesizes that it folds back in on itself along the observatory’s line of sight as the Horsehead Nebula forms. Behind this ridge, they noticed a cold mass of dense material that seemed to be shielded from these interactions – which they suspect would go on to form a new star system.

This made the observations particularly exciting, as it allowed astronomers to see magnetic field lines in regions like the Horsehead Nebula for the first time. As Patel added, “This gives us insight into how stars continue to form even in regions like Horsehead, where the cold gas that provides material for new stars is being eroded by photons from nearby, hot, young stars. We expect that our Sun formed as part of a cluster of stars, Thus looking at how stars formed in the Horsehead Nebula may give us insight into our solar system’s past.”

Although an iconic astrological being, Go’s Notes It was the first time anyone had attempted to visualize its own magnetic field. “When I heard about the Maunakea Scholars Program, I was excited,” said Joe. “It seemed to me a great opportunity to use telescopes at Maunakea. I chose to study the Horsehead Nebula because I thought it was beautiful, and I didn’t find much research on it.”