Nearest supernova in a decade confirms such stars lose mass prior to exploding

Gemini North image of supernova in Pinwheel Galaxy
Arrow points to supernova. Click for original image,
taken by the Gemini North telescope in Hawaii.

Astronomers making a detailed analysis of the data from the nearest supernova in a decade, SN 2023ixf and located in the Pinwheel Galaxy only 20 million light years away, has confirmed what other research had suggested, that such stars lose significant mass prior to exploding.

Within hours of going supernova, core-collapse supernovae produce a flash of light that occurs when the shock wave from the explosion reaches the outer edge of the star. SN 2023ixf, however, produced a light curve that didn’t seem to fit this expected behavior. To better understand SN 2023ixf’s shock breakout, a team of scientists led by CfA postdoctoral fellow Daichi Hiramatsu analyzed data from the 1.5m Tillinghast Telescope, 1.2m telescope, and MMT at the Fred Lawrence Whipple Observatory, a CfA facility located in Arizona, as well as data from the Global Supernova Project— a key project of the Las Cumbres Observatory, NASA’s Neil Gehrels Swift Observatory, and many others. This multi-wavelength study, which was published this week in The Astrophysical Journal Letters, revealed that, in sharp contradiction to expectations and stellar evolution theory, SN 2023ixf’s shock breakout was delayed by several days.

“The delayed shock breakout is direct evidence for the presence of dense material from recent mass loss,” said Hiramatsu, adding that such extreme mass loss is atypical of Type II supernovae. “Our new observations revealed a significant and unexpected amount of mass loss— close to the mass of the Sun— in the final year prior to explosion.”

The press release overstates the surprise of this discovery. Research in the last two decades of massive stars that are thought to be the progenitors of supernovae has shown that they lose mass in great amounts during eruptions. It was therefore not that surprising that this star experienced its own eruption prior to going supernova.

Update on the ongoing research of the closest supernovae in a decade

Gemini North image of supernova in Pinwheel Galaxy
Click for original image, taken by the Gemini North telescope in Hawaii.

Link here. Though the press release from UC-Berkeley focuses mostly of research being done by its astronomers, it also provides a very good overview of what all astronomers worldwide have been learning since Supernova SN 2023ixf was first discovered by amateur astronomer Koichi Itagaki in Japan on May 19, 2023 in the Pinwheel Galaxy, only 20 million light years away. This tidbit is probably the most significant:

Another group of astronomers led by Ryan Chornock, a UC Berkeley adjunct associate professor of astronomy, gathered spectroscopic data using the same telescope at Lick Observatory. Graduate student Wynn Jacobson-Galán and professor Raffaella Margutti analyzed the data to reconstruct the pre- and post-explosion history of the star, and found evidence that it had shed gas for the previous three to six years before collapsing and exploding. The amount of gas shed or ejected before the explosion could have been 5% of its total mass — enough to create a dense cloud of material through which the supernova ejecta had to plow.

Such data is going to help astronomers better predict when a star is about to go boom, by identifying similar behavior.

Gemini telescope in Hawaii fixed, captures nearby supernova

Gemini North image of supernova in Pinwheel Galaxy
Click for original image.

The Gemini telescope in Hawaii, which was damaged in 2022 during normal maintenance operations, has now been fixed and resumed observations, beginning with a spectacular image of the newly discovered supernova in the Pinwheel Galaxy, only 20 million light years away.

The Gemini North telescope, one half of the International Gemini Observatory operated by NSF’s NOIRLab, has returned from a seven-month hiatus literally with a bang, as it has captured the spectacular aftermath of a supernova, a massive star that exploded in the large, face-on, spiral Pinwheel Galaxy (Messier 101). The supernova, named SN 2023ixf [as indicated by the arrow], was discovered on 19 May by amateur astronomer Koichi Itagaki.

Since its discovery, observers around the globe have pointed their telescopes toward Messier 101 to get a look at the burst of light. Over the coming months, Gemini North will allow astronomers to study how the light from the supernova fades and how its spectrum evolves over time, helping astronomers better understand the physics of such explosions.

As one of the closest supernova to occur in years, SN 2023ixf has become a major target by astronomers. This type of supernova signals the collapse and death of a star 8 to 10 times the mass of the Sun. Since the life cycle of such massive stars is not yet fully understood, this nearby supernova provides a great opportunity for astronomers to learn more.

Watch a still brightening new supernova only 20 million light years away

A new still brightening supernova has been discovered in the Pinwheel Galaxy, also known as Messier 101, only 20 million light years away, one of the closest such supernovae in years.

The discovery was made on May 19, 2023. Because the supernova is so close, it was discovered very early in its explosion and is still brightening to maximum. It is also an object that ordinary amateur astronomers can spot using their own telescopes. The Pinwheel Galaxy is located in the Big Dipper, making it a good target for amateurs in the northern hemisphere.

A live stream of the supernovae, dubbed SN 2023ixf, is also being broadcast today by the Virtual Telescope Project, and will be available here starting at 3 pm (Pacific).

No supernovae have occurred within our own galaxy, the Milky Way, since the invention of the telescope, so any such event in a nearby galaxy is an important opportunity for astronomers to learn more about these explosions.

New data suggests that the crash of two white dwarf stars caused the nearest supernovae in 25 years

New data has found that the crash of two white dwarf stars not only caused the nearest supernova in 25 years, but appear to be the prime cause for these types of supernovae.

The data also says that there are no white dwarf primary systems in the Milky Way that are candidates to go supernova in this way. Thus, we can all sleep easy tonight!

The closest supernovae in almost 25 years

Astronomers have spotted the closest supernovae in almost 25 years, only 21 million light years away.

The supernova, dubbed PTF 11kly, occurred in the Pinwheel Galaxy, located in the “Big Dipper,” otherwise known as the Ursa Major constellation. It was discovered by the Palomar Transient Factory (PTF) survey, which is designed to observe and uncover astronomical events as they happen. “We caught this supernova very soon after explosion. PTF 11kly is getting brighter by the minute. It’s already 20 times brighter than it was yesterday,” said Peter Nugent, the senior scientist at Berkeley Lab who first spotted the supernova. Nugent is also an adjunct professor of astronomy at UC Berkeley. “Observing PTF 11kly unfold should be a wild ride. It is an instant cosmic classic.”

Astronomers expect the supernova to continue to brighten over the next two weeks, when it should be visible to anyone using binoculars.