Tag: nova

New nova spotted and now visible to the naked eye

2:39 pm

Astronomers have now spotted a brand new nova in the southern hemisphere that has quickly brightened so that is now just visible to the naked eye.

On June 12th (June 12.9 UT), the All-Sky Automated Survey for Supernovae (ASAS-SN) discovered a new 8.7-magnitude stellar object in Lupus. Not long after, Yusuke Tampo, with the South African Astronomical Observatory (University of Cape Town), obtained a spectrum of the “new star” and identified it as a classical nova based on its spectral features and dramatic increase in brightness.

The nova went through a slew of temporary names — AT 2025nlr, ASASSN-25cm, and N Lup 2025 — until receiving its official designation V462 Lupi on June 16th. Since discovery, the nova has brightened rapidly. As of 3 p.m. Eastern Time June 17th, it’s at magnitude 6.1, and visible without optical aid from a dark-sky location. Its rise has been phenomenal when you consider that prior to the explosion, the progenitor star was approximately magnitude 22.3 (in the blue band) according to American Association for Variable Stars (AAVSO) observer Sebastián Otero, who dug up an older image from a photographic plate.

Though in the southern hemisphere, this nova star is also visible in the northern hemisphere to the mid-latitudes. The article at the link provides some details if you wish to try spotting it.

Novae occur when a central heavy white dwarf star robs enough material from its closely orbiting stellar companion. When enough material piles up on the surface of the white dwarf it goes critical, resulting in a thermonuclear explosion strong enough to produce the nova.

Whether the nova will continue to brighten remains unknown, but I guarantee that a plethora of amateur astronomers will watching to find out.

Hat tip to BtB’s stringer Jay.

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Stoke Space raises another $260 million, more than doubling its private capital

10:22 am

Stoke's Nova rocket
Stoke’s Nova rocket

The rocket startup Stoke Space, which is attempting to develop its own fully reusable two stage rocket, announced yesterday that it has successfully raised $260 million of private investment capital in its most recent funding round, more that doubling what it had raised previously and bringing the total raised by the company to $480 million.

The funding round involves new and existing investors including Breakthrough Energy Ventures, Glade Brook Capital Partners, Industrious Ventures, Leitmotif, Point72 Ventures, Seven Seven Six, the University of Michigan, Woven Capital, and Y Combinator, among others.

The company’s Nova rocket will use what has become the standard for first stage re-use, a vertical take-off and landing. Its second stage however will also be reusable, something no one has yet succeeded in doing, and Stoke intends to do it in a radical manner. Rather than use a single nozzle on its upper stage, it has instead gone with a new design whereby thrust is released through a string small nozzles placed in a ring on the bottom outside of the stage. The base of the stage can thus get a heat shield. The plan is to have the stage return much like many returnable capsules, with the small nozzles then used to provide control and thrust during landing.

This new influx of cash indicates renewed confidence in the company among the investor class. Its recent successful test of its Zenith first stage engines probably help fuel that confidence.

It had hoped to do its first test launch this year from Cape Canaveral, but has recently been burdened with new environmental red tape that might impact those plans.

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Rocket startup Stoke Space completes static fire test of first stage engine

10:02 am

Stoke's Nova rocket
Stoke’s Nova rocket

The rocket startup Stoke Space revealed yesterday that it has completed a static fire test of the first stage engine it will use on its Nova rocket, shown in the graphic to the right.

The test, which was not the first for this engine, proved out several new technologies.

Stoke Space called the test significant for several reasons. It’s the first hotfire of the company’s Block 2 (flight layout) stage 1 engine, and this engine architecture — called full-flow staged combustion (FFSC) — is considered particularly challenging. Only two entities in the world — Stoke and SpaceX — have successfully developed FFSC engines. … Stoke’s stage 1 engine is a liquified natural gas/liquid oxygen engine capable of producing 100,000 pounds of thrust. The duration of the test was not revealed.

It was the first time Stoke has tested on its new vertical test stand in Moses Lake. The company’s testing philosophy is that you must “test like you fly,” and it believes vertical testing is key to engine development.

Nor is the first stage engine the only technological innovation. Nova’s second stage uses a radical design whereby the engine releases its thrust through a ring of small nozzles on the outside perimeter of the stage, rather than a single central nozzle. This design is what the company hopes will allow it to return that upper stage intact for reuse.

The four year old company has raised $100 million in investment capital, but has also faced environmental red tape from the Space Force for its launch facility at Cape Canaveral. It had previously targeted 2025 for the first test flights of Nova, but that schedule appears unlikely because of this red tape.

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The uncertainty of science: Star refuses to erupt when predicted

9:48 am

Based on records of two past eruptions approximately eighty years apart, astronomers had predicted that the binary star system T Coronae Borealis would erupt sometime in September 2024, brightening from magnitude 10 to as much as magnitude 2, making it one of the sky’s brighter stars for a short while.

That eruption however has so far not taken place.

“We know it has to happen,” astrophysicist Elizabeth Hays, who is watching T CrB every day using NASA’s Fermi gamma-ray space telescope, told Space.com in a recent interview. “We just can’t pin it down to the month.”

The unpredictability stems partly from limited historical records of T CrB’s outbursts. Only two such eruptions have been definitively observed in recent history: on May 12, 1866, when a star’s outburst briefly outshined all the stars in its constellation, reaching magnitude 2.0, and again on February 9, 1946, when it peaked at magnitude 3.0. These events appear to follow the star’s roughly 80-year cycle, suggesting that the next outburst may not occur until 2026. [emphasis mine]

The eruptions are thought to occur because the system’s denser white dwarf star pulls material from the lighter orbiting red giant. Over time that material accumulates on the surface of the white dwarf until it reaches critical mass, triggering a nuclear explosion that we see as the star’s brightening.

Astronomers have assumed this process is predictable, but in truth it really is not. For example, the star has brightened at other times, in 1938 and again in 2015, though not as much. These other brightenings suggest a great deal of uncertainty in the rate in which material accumulates, as well as how much is needed to trigger a nuclear burst.

Because of the possibility however of a burst at any time, astronomers have been poised eagerly now for months, observing the star regularly with the many orbiting telescopes that can observe it not only in optical wavelengths but in gamma, X-rays, and infrared. The latter capabilities didn’t exist in previous eruptions, and are now able to tell them things about the system that was impossible for earlier astronomers.

Assuming the eruption occurs at all. Despite the certainty of the astronomer’s quote highlighted above, there is no certainty here. This star system will do whatever it wants, despite the predictions of mere human beings.

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Rocket startup Stoke Space is saddled with the same red tape as SpaceX

10:06 am

Stoke's Nova rocket
Stoke’s Nova rocket

We’re from the government and we’re here to help you! The rocket startup Stoke Space appears to be struggling with the same kind of environmental red tape that is hindering SpaceX, though in Stoke’s case the red tape appears absurdly unnecessary.

Stoke is the only company besides SpaceX developing a rocket with both its first and second stages returning to Earth to land vertically and then be reused. Unlike SpaceX Starship/Superheavy, which is gigantic and revolutionary in all ways, Stoke’s Nova rocket is comparable in size to the hundreds of rockets that have launched from Florida since the 1960s. Based on that six-decade track record, it would seem that getting rights to launch Nova (but not for its return) would be considered basic and routine, requiring little complex bureaucracy.

Hah! Fooled you!

Before any of this can take place, the Space Force must complete its “environmental assessment” of the company’s plans at LC-14 [the launchpad used for John Glenn’s first orbital mission and many others subsequently], in order to evaluate how repeat launches will affect local flora and fauna. These assessments are mandatory under federal law, and they can often take months — but the upside is that they provide a closer look at a company’s operational plans.

» Read more

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Update on Cape Canaveral work by multiple launch companies

9:24 am

Link here. The article provides a nice summary of the construction work by Blue Origin, Stoke Space, and SpaceX at the cape, all leading to future launches and greater capabilities.

Blue Origin is still pushing for a September 29, 2024 first launch of its New Glenn orbital rocket. SpaceX is continuing work on its new Starship/Superheavy facilities as well as installing upgrades to its Falcon launchpads. The most interesting tidbit however is was about Stoke Space and its proposed Nova rocket:

The first two flights of Nova are planned for 2025, while 10 flights are planned for both 2026 and 2027. Initial flights of Nova will be expendable, with full reusability of the first and second stages coming later.

Stoke’s primary goal has been to make this rocket entirely reusable. It apparently plans to begin launching and do recovery tests as it goes until it achieves that reusability later.

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Stoke Space test fires its first stage engine for the first time

10:02 am

The rocket startup Stoke Space has successfully completed the first static fire test of the methane-fueled rocket engine that will be used on the first stage of its entirely reusable Nova rocket.

The engine, designed to produce up to 100,000 pounds-force of thrust, went up to 50% of its rated thrust in the two-second test. The goal of the test was to see how the engine started up and shut down, Andy Lapsa, chief executive of Stoke, said in an interview. “All of the complexity and a lot of the risk is in that startup transient and shutdown transient,” he said. “The duration of the test was short because the goal was to demonstrate the transient and then back out.”

The engine uses a design called full-flow staged combustion, where both the engine’s fuel and oxidizer — liquified natural gas and liquid oxygen, respectively — go through separate preburners before going into the main combustion chamber. That approach offers greater efficiency and a longer engine life, but is more complex to develop. It is currently used only on SpaceX’s Raptor engines that power its Starship vehicle.

The rocket’s upper stage uses hydrogen as its fuel, as well as a radical nozzle design. Instead of a single large nozzle, the thrust is released from a ring of tiny outlets at the permeter of the stage. It is hoped this design will better protect the system during re-entry from orbit, while allowing for more precise control upon landing, and thus make it possible to reuse the upper stage.

The first test launch is presently scheduled for 2025. This new engine test makes that date more realistic.

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A relatively dim star is expected to become one of the brightest in the sky later this year

9:49 am

As it has done twice before at intervals of 80 years, a relatively dim star is expected to go nova later this year, becoming for a short time one of the brightest stars in the sky.

Located in the Northern Crown constellation, T Coronae Borealis (T CrB) is a pretty average looking star, most of the time. With a brightness of about magnitude +10, it’s right on the limits of what you could see with a pair of binoculars, and even if you do go looking there’s not much to see.

At least, that’s the case for about 79 out of 80 years. But on that 80th year, the star suddenly brightens drastically up to around magnitude +2, which puts it on par with the north star Polaris. That makes it one of the brightest stars in the night sky, easily visible with the naked eye even when washed out by city lights. This once-in-a-lifetime outburst last occurred in 1946, and before that 1866.

And lucky for stargazers, T CrB seems to be about two years ahead of schedule, with astronomers predicting it will flare up again between March and September 2024. It’ll appear as a bright ‘new’ star for a few days with the naked eye, and a little over a week with binoculars, before it settles down again for another few decades. Astronomers noticed last year that T CrB had started to dim, which data from 1945 showed preceded the last brightening event.

The star is actually a binary, made up of a white dwarf and a red giant. The white dwarf is pulling material from the red giant, and as that new material piles up, it eventually gathers enough mass to go critical and produce a thermonuclear explosion. The result is a nova, a smaller version of a supernova that unlike supernovae occurs repeatedly.

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Update on rocket startup Stoke Space’s effort to make completely reusable rocket

10:07 am

Link here. This Nasaspaceflight.com article provides an excellent update on the status of the development of Stoke’s Nova rocket, which will have a radical new engine design in its upper stage, using a ring of small nozzles rather than one single central one. That design will allow the upper stage to return to Earth for reuse, something that no other rocket now in use at present can do.

Stoke Space recently carried out the first test of the full-size 30-thruster version of the innovative engine that the company is producing for its in-development second stage. This will be an integral part of its future Nova rocket, which aims to be a fully reusable medium lifter.

The engine test took place on Feb. 26 and follows the engine’s first test flight on its prototype vehicle, Hopper 2, in September 2023. Although fitted with only 15 chambers for that flight, Hopper 2 flew for 15 seconds, achieved a maximum altitude of 30 feet, traversed to a landing site, and touched down softly.

The article includes a lot of interesting technical details about this upper stage and what engineers are learning about this radical engine design. Worth reading. At present Stoke is the only company other than SpaceX attempting to make its upper stage fully reusable. If successful it will jump ahead of everyone else.

No launch schedule however for its new rocket was revealed in this report, so it might be awhile, if ever, before any of this bears fruit.

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Stoke Space raises $100 million in private investment capital

9:12 am

The rocket startup Stoke Space, which is developing a radically new engine concept for its rockets, has now successfully raised $100 million in private investment capital.

This investment more than doubles the company’s total funding, which now sits at $175 million. The company also announced the official name of its first rocket: Nova.

The funding round was led by Industrious Ventures with participation from the University of Michigan, Sparta Group, Long Journey, and others. Existing investors Breakthrough Energy, YCombinator, Point72 Ventures, NFX, MaC Ventures, Toyota Ventures, and In-Q-Tel also participated. This latest funding round is evidence of strong demand for Stoke’s services, its growing success, and the confidence of investors in its future. As part of this round of fundraising Steve Angel, Chairman of the Board, Linde plc, will join Stoke’s Board of Directors. Angel is also the former CEO of Linde and a member of the Board of Directors of GE.

The company says it will use this money to develop the rocket’s first stage engines, which will follow the same ring nozzle design of its upper stage, a prototype of which it successfully test flew on a short hop last month. Under that design, the engine doesn’t have one central nozzle, but instead the thrust is funnelled out of a ring of tiny nozzles that circle the stage’s outer perimeter. The company believes this design will allow it to return its upper stage safely from orbit for re-use.

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New data makes past nova too bright, but not bright enough to be supernova

9:21 am

The uncertainty of science: Astronomers, using new data from the Gemini North ground-based telescope, have found that a star that brightened in 1670 and was labeled a nova is much farther away than previously thought, which means that 1670 eruption was far too powerful for a nova, but not powerful enough to make it a supernova.

By measuring both the speed of the nebula’s expansion and how much the outermost wisps had moved during the last ten years, and accounting for the tilt of the nebula on the night sky, which had been estimated earlier by others, the team determined that CK Vulpeculae lies approximately 10,000 light-years distant from the Sun — about five times as far away as previously thought. That implies that the 1670 explosion was far brighter, releasing roughly 25 times more energy than previously estimated [4]. This much larger estimate of the amount of energy released means that whatever event caused the sudden appearance of CK Vulpeculae in 1670 was far more violent than a simple nova.

“In terms of energy released, our finding places CK Vulpeculae roughly midway between a nova and a supernova,” commented Evans. “[T]he cause — or causes — of the outbursts of this intermediate class of objects remain unknown. I think we all know what CK Vulpeculae isn’t, but no one knows what it is.”

Recent research has also suggested that the cause of the eruption was not from the interaction of a binary system with one normal star and a white dwarf, as believed for decades, but possibly a binary system with a brown dwarf, or a red giant star, or two normal stars. All are remain possible, none however have been confirmed.

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Astronomers predict binary stellar merger in 2022

9:37 am

Astronomers are predicting that a two binary stars that orbit so close together that they share an atmosphere will merge and explode as a bright red nova in approximately five years.

According to the actual paper [pdf], they also predict that this will be a naked eye event, visible in the northern hemisphere.

Note that a red nova is not a supernova. These are different types of explosions, with the supernova many times more powerful and rare. Nonetheless, the event itself will spectacular, should the prediction be correct.

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A star that went nova last week is now visible to the naked eye.

2:07 pm

A star that went nova last week is now visible to the naked eye.

“Nova Delphini 2013 is among the 30 brightest novae ever recorded,” says S&T editor in chief Robert Naeye. “It’s a wonderful target for backyard observers, given that it’s visible to the naked eye and relatively easy to find. But it’s also attracting the intense interest of scientists, who are using a wide assortment of telescopes and astronomical satellites to better understand these enigmatic explosions.”

Though related scientifically to certain kinds of supernovae, this is not a supernova. Nonetheless, it is rare for these events to be bright enough to be visible to the naked eye. Go outside tonight and take a look!

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