The NASA/ESA Hubble Space Telescope has captured a striking photo of a little-known galaxy called WISEA J070815.11+210422.3.
SN 2022aajn is visible as a blue dot at the center of this Hubble image, brightening the hazy body of WISEA J070815.11+210422.3. Image credit: NASA / ESA / Hubble / R.J. Foley, UC Santa Cruz.
WISEA J070815.11+210422.3 is located approximately 600 million light-years away in the constellation of Gemini.
This image was taken roughly two months after the SN 2022aajn supernova event occurred in the galaxy.
“Other than the announcement of its discovery in November 2022, SN 2022aajn has never been the subject of published research,” the Hubble astronomers wrote in a statement.
“Why, then, would Hubble observe this supernova? SN 2022aajn is what’s known as a Type Ia supernova, which results from the explosion of the core of a dead star.”
Type Ia supernovae help astronomers measure the distance to faraway galaxies.
“This is possible because Type Ia supernovae are thought to be of the same intrinsic luminosity — no matter how bright they seem from Earth, they put out the same amount of light as other Type Ia supernovae,” the researchers wrote.
“Thus, by comparing the observed brightness to the expected brightness, we can calculate the distance to the supernova and its host galaxy.”
“This seemingly simple measurement method is complicated by cosmic dust.”
“The farther away a supernova is, the fainter and redder it will appear — but intergalactic dust can make a supernova appear fainter and redder as well.”
“To understand this complication, we will use Hubble to survey a total of 100 Type Ia supernovae in seven wavelength bands from the ultraviolet to the near-infrared.”
The color image of WISEA J070815.11+210422.3 was made from separate exposures taken in the infrared region of the spectrum with Hubble’s Wide Field Camera 3 (WFC3).
Four filters were used to sample various infrared wavelengths. The color results from assigning different hues to each monochromatic image associated with an individual filter.
“This image combines data taken at four infrared wavelengths,” the scientists wrote.
“Infrared light passes through dust more easily than visible or ultraviolet light.”
“By comparing the brightness of the sampled supernovae across different wavelengths, we can disentangle the effects of dust and distance, helping to improve measurements of galaxies billions of light-years away and even the expansion of our Universe.”
