by The first data from a new telescope array is in.
The Condor Array has revealed a glimpse of a distant dwarf nova – a sight that offers astronomers a new, very low-brightness view of the universe to marvel at.
Condor consists of six refracting telescopes, which are joined together by computers to create a giant telescope conglomerate that can detect and study objects that are too faint to be seen by normal. single telescope. One of the first missions assigned to Condor was to target the dwarf nova named Z Camelopardalis. In particular, American Museum of Natural History researcher Michael M. Shara wanted to know if this dwarf Nova is related to a “new star” recorded by Imperial Chinese astronomers in 77 BCE.
The new telescope array not only strengthened this link, but also discovered interesting, never-before-seen features of the dwarf nova. Since astronomer Henry Park Hollis first saw it in visible light in 1904, the object has been studied in detail. So, it is quite exciting to get new information about it.
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Shy Novas coming out of their shells
Dwarf novas are a special class of supernova explosion that occur in one of two ways.
The first way a white dwarf stellar remnant gradually siphons material from a companion star to its own surface. Such siphoning continues until the process triggers a thermonuclear explosion. The second possible path as a result of a dwarf nova, on the other hand, has to do with a huge amount of material from a companion star suddenly getting “dumped” on the white dwarf with the same thermonuclear result.
In January 2007, an image of Z Camelopardalis, taken by the 4-meter telescope at the Kitt Peak National Observatory, showed that it is surrounded by a partial shell of gas that may have been emitted during that thermonuclear explosion.
To test this idea, Shara and her colleagues imaged Z Camelopardalis with Condor in November 2021 and compared this to the 2007 image. This allowed them to measure how much the shell had grown over time. time and therefore the speed at which the gas moved out.
This confirmed to the team that the shell was expanding at a rate consistent with an explosion that occurred about 2,000 years ago, suggesting that this explosion could be the “new star” seen in 77 BCE China.
Shara and the team were surprised to see that Condor was able to distinguish the entire gas shell around Z Camelopardalis. The new telescope array also saw a second, larger (but smaller) shell of gas around the dwarf Nova. Such a shell is too deep to be seen with ordinary telescopes.
“This is the first ever example of two concentric shells surrounding a dwarf nova, and confirms a long-held hypothesis that concentric shells must surround frequently erupting novae of relatively massive white dwarfs,” Shara said. .
However, this is not the extent of the nova discovery revealed in the first Condor data drop.
Using the telescope, Professor Kenneth M. Lanzetta and the team from Stonybrook University observed an extremely faint shell of gas surrounding a “reflex nova.” This class of Nova is also caused by white dwarfs accreting material and becoming unstable, but explosions occur repeatedly on a time scale of less than 100 years.
One recurrent nova, M31N 2008-12a, is located in the nearest large galaxy to the Milky Way, Andromeda. It bounces every year and is surrounded by a “super-remnant” made of dust shells that spread out for about 44 million light years. These shells should also be surrounded by other reflexive Novas – but, so far, they have not been.
Lanzetta and colleagues saw a shell around the recurrent nova (KT Eri), which blows its top every 40 to 50 years. This shell is about 50 times larger than previously observed, the team says, and appears to be the result of multiple nova shells crashing into each other over thousands of years.
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The first batch of Condor data also contains more treats, with Lanzetta and colleagues also using the telescope to study stellar streams around the galaxy NGC 5907, a known spiral galaxy located about 50 million light-years from Earth. These streams of stars are created when the larger galaxies that orbit their satellite galaxies gravitationally pull on the satellites, disrupting them and pulling out the stars.
Condor followed up on two previous images of NGC 5907, located 50 million light-years from Earth. One in 2010 showed stellar streams forming two helix-like loops around the galaxy, but another in 2019 lacked those features.
Like the last image, this helix-like feature also appeared to be missing from the Condor observation of NGC 5907. The team suggested it was an artifact related to image processing of the 2010 image.
The results of the Condor Array Telescope are published over a series of four papers published in the journal Monthly Notices of the Royal Astronomical Society
