Tag: astronomy

Hawaiian TMT protesters found not guilty of obstructing the road they obstructed

9:05 am

The law for thee but not for me: An Hawaiian judge has ruled that the protesters of the Thirty Meter Telesecope (TMT) who had obstructed the access road to the top of Mauna Kea are not guilty of obstructing that road.

[I]n announcing her verdict, the judge noted that during the trial, officials testified that the access road was closed and there were no permits issued for oversized vehicles. “Evidence that Mauna Kea access road was closed or restricted to the public, coupled with no permits, equals no obstruction,” Laubach said. “There would be no unreasonable inconvenience or hazard.”

The state failed to meet its burden beyond a reasonable doubt, she said.

This ruling is a joke. The reason the officials closed the road was because the protesters were there. The officials did not want anyone hurt by the oversized trucks that had legal permission to drive through carrying TMT construction equipment.

Such a ruling however is not a surprise. From top to bottom Hawaii’s government in controlled by the Democratic Party. The judge almost certainly was a Democrat. The Democrats favor the bigoted anti-white and anti-technology agenda of the protesters, and have gone out of their way to help them in their protests.

In general, protesters for Democratic Party causes can loot, burn, kill, obstruct traffic, and do all sorts of violent things — including physically attacking women and children in a park in Portland — and are either never arrested, quickly released on dropped charges, or found innocent.

Be a conservative and spend a dozen minutes inside the Capitol Building taking a few selfies, however, and you will find yourself imprisoned for months, with no charges brought and no sign they ever will be brought. You are guilty, and you will be punished. How dare you do anything that opposes the Democratic Party and its storm trooper thugs?

TMT is never going to be built in Hawaii. In fact, I am beginning to doubt it will ever be built anywhere. Considering the increasing difficulty that ground-based astronomy is going to have dealing with the many satellite constellations now being launched, it is very possible the support for the telescope will begin to dry up. And maybe this failure will be a signal to astronomers that they should finally begin spending their money on space-based optical telescopes.

Meanwhile, Hawaii has become a place hostile to science, to new knowledge, and even to tourism. The dark age there has come quite quickly.

10 comments

Scientists: Betelgeuse dimmed because of giant dark spot on surface

12:00 pm

The uncertainty of science: A new study by scientists in China now proposes that the dimming of the red giant star Betelgeuse in 2019-2020 was because of a giant dark and cold spot on its surface.

When Betelgeuse was at its dimmest on Jan. 31, 2020, its effective temperature — meaning, the temperature calculated from its emitted radiation — was measured at 3,476 degrees Kelvin (about 5,800 degrees Fahrenheit or 3,200 degrees Celsius.)

But once the star was back to a normal luminosity, measurements indicated an almost 5% temperature rise to 3,646 Kelvin (roughly 6,100 F or 3,370 degrees C.)

…[T]he astronomers … concluded it is unlikely the entire surface cooled temporarily by that amount. Rather, it must have been a sunspot — or rather, a “star spot” — blocking some of Betelgeuse’s radiation from escaping, they said.

This new hypothesis aligns partly with others that say it was a combination of a dark spot and intevening dust that caused the dimming.

None of these hypotheses however “solve” the mystery. Too little concrete information exists at present to do that.

0 comments

For the first time astronomers measure the rotation of exoplanets

10:10 am

The uncertainty of science: Using the Keck Telescope in Hawaii astronomers for the first time have measured the rotation of several exoplanets orbiting the star HR8799, about 129 light years away.

Using the state-of-the-art Keck Planet Imager and Characterizer (KPIC) on the Keck II telescope atop Hawaiʻi Island’s Maunakea, astronomers found that the minimum rotation speeds of HR 8799 planets d and e clocked in at 10.1 km/s and 15 km/s, respectively. This translates to a length of day that could be as short as three hours or could be up to 24 hours such as on Earth depending on the axial tilts of the HR 8799 planets, which are currently undetermined. For context, one day on Jupiter lasts nearly 10 hours; its rotation speed is about 12.7 km/s.

As for the other two planets, the team was able to constrain the spin of HR 8799 c to an upper limit of less than 14 km/s; planet b’s rotation measurement was inconclusive.

These results are somewhat uncertain, as are any conclusions theorists try to draw from them. Even if confirmed, the sample is so small it doesn’t tell us anything yet about overall trends in planet formation or the expected spin rate of planets as they form.

Nonetheless, the detection appears valid and thus a scientific triumph. Astronomers have been telling me for years that figuring out ways to find out more about exoplanets is going to become the next hot subject in astronomy. This result illustrates this.

1 comment

An astrophysicist explains cosmology’s theoretical failures

8:37 am

Link here. The astrophysicist, Paul Sutter, does a very nice job of outlining the conundrum that has been causing astrophysicists to tear their hair out for the past decade-plus.

In the two decades since astronomers discovered dark energy, we’ve come upon a little hitch: Measurements of the expansion rate of the universe (and so its age) from both the CMB [cosmic microwave background] and supernovas have gotten ever more precise, but they’re starting to disagree. We’re not talking much; the two methods are separated by only 10 million or 20 million years in estimating the 13.77-billion-year history of the universe. But we’re operating at such a level of precision that it’s worth talking about.

If anything, this failure for two measurements of data spanning billions of light years — which is billions in both time and space — is a perfect illustration of the uncertainty of science. Astrophysicists are trying to come up with answers based on data that is quite thin, with many gaps in knowledge, and carries with it many assumptions. It therefore is actually surprising that these two numbers agree as well as they do.

Sutter, being in the CMB camp, puts most of the blame for this failure on the uncertainty of what we know about supernovae. He could very well be right. The assumptions about supernovae used to measure the expansion rate of the universe are many. There is also a lot of gaps in our knowledge, including a full understanding of the process that produces supernovae.

Sutter however I think puts too much faith in theoretical conclusions of the astrophysics community that have determined the age of the universe based on the CMB. The uncertainties here are as great. Good scientists should remain skeptical of this as well. Our knowledge of physics is still incomplete. Physicists really don’t know all the answers, yet.

In the end, Sutter however does pin down the biggest problem in cosmology:

The “crisis” is a good excuse to keep writing papers, because we’ve been stumped by dark energy for over two decades, with a lot of work and not much understanding. In a sense, many cosmologists want to keep the crisis going, because as long as it exists, they have something to talk about other than counting down the years to the next big mission.

In other words, the discussion now is sometimes less about science and theories and cosmology, but instead about funding and career promotion. What a shock!

11 comments

The Oort Cloud: what little is known

5:47 pm

Link here. This is one of the best articles on the theorized Oort Cloud, in that right off the bat the author recognizes this important fact:

We know so little about it that its very existence is theoretical — the material that makes up this cloud has never been glimpsed by even our most powerful telescopes, except when some of it breaks free.

The cloud’s existence is extrapolated from the arrival of long period comets, and seems to make sense. Yet, without any direct observations it remains a theory only, and an unproven one at that.

4 comments

Astronomers detect for the first time an accretion disk around an exoplanet

8:43 am

The exoplanet and its accretion disk
Click for full image.

Using the Atacama Large Millimetre/submillimeter Array (ALMA) in Chile, astronomers have made the first confirmed images of a moon-forming accretion disk around another a very young exoplanet.

The photo to the right shows this, with the top image the wide view showing the exoplanet in its orbit around the star, in an area inside the star’s own accretion disk (the larger ring) that the planet has apparently cleared of debris as it gathered itself. The bottom image zooms into the planet to show its own disk of material.

From the press release:

The disc in question, called a circumplanetary disc, surrounds the exoplanet PDS 70c, one of two giant, Jupiter-like planets orbiting a star nearly 400 light-years away. Astronomers had found hints of a “moon-forming” disc around this exoplanet before but, since they could not clearly tell the disc apart from its surrounding environment, they could not confirm its detection — until now.

In addition, with the help of ALMA, Benisty and her team found that the disc has about the same diameter as the distance from our Sun to the Earth and enough mass to form up to three satellites the size of the Moon.

The exoplanet’s disk is thus very large compared to our solar system, but that isn’t surprising considering the difficulty of observing it at such distances. Disks comparable in size to our solar system and the Earth-Moon system are simply too small for any telescope to yet image in this way.

The new data also found this interesting fact: The other known Jupiter-like exoplanet in this system does not have its own accretion disk or any visible debris orbiting it. Why one planet still has such debris and the other does not is a mystery related to the formation of solar systems that is at present not understood.

3 comments

Hubble returned to science operations

8:49 am

Engineers today completed their testing of their computer hardware fix on the Hubble Space Telescope and took it out of safe mode, allowing science observations to resume after more than a month.

The first observation is scheduled for Saturday afternoon after some instrument calibrations are completed. Most observations missed while science operations were suspended will be rescheduled for a later date.

Now let us all pray that there are no more major failures for the next few years until the U.S. capabilities in space grow and a relatively fast mission to repair the telescope is possible.

12 comments

Engineers report Hubble fix appears successfully

8:50 am

Engineers this morning announced that their attempt to switch to backup computer hardware on the Hubble Space Telescope was successful.

The switch included bringing online the backup Power Control Unit (PCU) and the backup Command Unit/Science Data Formatter (CU/SDF) on the other side of the Science Instrument and Command & Data Handling (SI C&DH) unit. The PCU distributes power to the SI C&DH components, and the CU/SDF sends and formats commands and data. In addition, other pieces of hardware onboard Hubble were switched to their alternate interfaces to connect to this backup side of the SI C&DH. Once these steps were completed, the backup payload computer on this same unit was turned on and loaded with flight software and brought up to normal operations mode.

They are now doing tests to make sure everything is working as expected, and preparing the telescope to bring it out of safe mode and resume science operations.

This is great news, but to bring everyone down to Earth, we must remember that Hubble no longer has any redundancy in this area. Should there be another similar computer failure, the telescope will then be dead in the water, with the only way to bring it back a manned or robotic mission — something we presently do not have the capacity to do — to replace these units.

5 comments

Hubble update: Engineers pinpoint issue, prepare to fix it

12:38 pm

In an update today on the status for bringing the Hubble Space Telescope back into science operations, the engineers say they think they have pinpointed the failed unit, and are ready to do the switch to a backup.

A series of multi-day tests, which included attempts to restart and reconfigure the computer and the backup computer, were not successful, but the information gathered from those activities has led the Hubble team to determine that the possible cause of the problem is in the Power Control Unit (PCU).

The PCU also resides on the SI C&DH unit. It ensures a steady voltage supply to the payload computer’s hardware. The PCU contains a power regulator that provides a constant five volts of electricity to the payload computer and its memory. A secondary protection circuit senses the voltage levels leaving the power regulator. If the voltage falls below or exceeds allowable levels, this secondary circuit tells the payload computer that it should cease operations. The team’s analysis suggests that either the voltage level from the regulator is outside of acceptable levels (thereby tripping the secondary protection circuit), or the secondary protection circuit has degraded over time and is stuck in this inhibit state.

Because no ground commands were able to reset the PCU, the Hubble team will be switching over to the backup side of the SI C&DH unit that contains the backup PCU. All testing of procedures for the switch and associated reviews have been completed, and NASA management has given approval to proceed. The switch will begin Thursday, July 15, and, if successful, it will take several days to completely return the observatory to normal science operations.

Engineers did a similar switch in 2008, so they are very confident it will work this time also. However, once done, the telescope will no longer have backups for any of these computer modules. The next failure in any of them will shut the telescope down, for good.

7 comments

Scientists successfully predict resumption of bursts from magnetar

12:14 pm

The uncertainty of science: Though they have no real idea why it happens, scientists have now successfully predicted the resumption of energetic bursts coming from a magnetar and according to schedule.

The researchers — Grossan and theoretical physicist and cosmologist Eric Linder from SSL and the Berkeley Center for Cosmological Physics and postdoctoral fellow Mikhail Denissenya from Nazarbayev University in Kazakhstan — discovered the pattern last year in bursts from a soft gamma repeater, SGR1935+2154, that is a magnetar, a prolific source of soft or lower energy gamma ray bursts and the only known source of fast radio bursts within our Milky Way galaxy. They found that the object emits bursts randomly, but only within regular four-month windows of time, each active window separated by three months of inactivity.

On March 19, the team uploaded a preprint claiming “periodic windowed behavior” in soft gamma bursts from SGR1935+2154 and predicted that these bursts would start up again after June 1 — following a three month hiatus — and could occur throughout a four-month window ending Oct. 7.

On June 24, three weeks into the window of activity, the first new burst from SGR1935+2154 was observed after the predicted three month gap, and nearly a dozen more bursts have been observed since, including one on July 6.

They made this prediction based on data going back to 2014 that showed the three-month-off/four-month-on pattern.

As to why this pattern exists, they presently have no idea. Theories have been proposed, such as starquakes activated by the magnetar’s fast rotation or blocking clouds of gas, but none are really very convincing, or are backed with enough data.

0 comments

Engineers successful complete simulation of Hubble repair

12:30 pm

Though the details released are sparse, engineers working to get the Hubble Space Telescope back in operation since it shut down due to a computer problem in mid-June report today that they have successfully completed a simulation of the procedures they need to do to fix the problem.

This is their entire report:

[The engineers] successfully completed a test of procedures that would be used to switch to backup hardware on Hubble in response to the payload computer problem. This switch could occur next week after further preparations and reviews.

Apparently, because the switch to backup hardware requires switching more than one unit, the sequence is important and following it correctly is critical. It appears they have now determined the correct sequence and will attempt it on Hubble next week.

0 comments

Hubble update: Engineers narrow possible failed hardware to one of two units

5:09 pm

Engineers working to pinpoint the cause of the computer hardware issue that has placed the Hubble Space Telescope in safe mode since June 13th have now narrowed the possible failed hardware to one of two units.

The source of the computer problem lies in the Science Instrument Command and Data Handling (SI C&DH) unit, where the payload computer resides. A few hardware pieces on the SI C&DH could be the culprit(s).

The team is currently scrutinizing the Command Unit/Science Data Formatter (CU/SDF), which sends and formats commands and data. They are also looking at a power regulator within the Power Control Unit, which is designed to ensure a steady voltage supply to the payload computer’s hardware. If one of these systems is determined to be the likely cause, the team must complete a more complicated operations procedure to switch to the backup units. This procedure would be more complex and riskier than those the team executed last week, which involved switching to the backup payload computer hardware and memory modules. To switch to the backup CU/SDF or power regulator, several other hardware boxes on the spacecraft must also be switched due to the way they are connected to the SI C&DH unit.

Over the next week or so, the team will review and update all of the operations procedures, commands and other related items necessary to perform the switch to backup hardware. They will then test their execution against a high-fidelity simulator.

The team performed a similar switch in 2008, which allowed Hubble to continue normal science operations after a CU/SDF module failed.

That such a switch was done successfully in the past is a very hopeful sign. However, it sounds as though they are not 100% sure they have pinpointed the actual issue, which means that this switch still might not fix the problem.

We can only wait and hope. And even if the fix works, Hubble will no longer have working backup units for these pieces of hardware. Should any of the backup that are now being activated fail, the telescope will fail, and this time it won’t be fixable with the equipment on board.

10 comments

Astronomers detect a white dwarf that is both the smallest and most massive ever found

10:04 am

Using an array of telescopes on the ground and in space, astronomers have discovered a white dwarf star that is both the smallest ever found while also being the most massive.

White dwarfs are the collapsed remnants of stars that were once about eight times the mass of our Sun or lighter. Our Sun, for example, after it first puffs up into a red giant in about 5 billion years, will ultimately slough off its outer layers and shrink down into a compact white dwarf. About 97 percent of all stars become white dwarfs.

While our Sun is alone in space without a stellar partner, many stars orbit around each other in pairs. The stars grow old together, and if they are both less than eight solar-masses, they will both evolve into white dwarfs.

The new discovery provides an example of what can happen after this phase. The pair of white dwarfs, which spiral around each other, lose energy in the form of gravitational waves and ultimately merge. If the dead stars are massive enough, they explode in what is called a type Ia supernova. But if they are below a certain mass threshold, they combine together into a new white dwarf that is heavier than either progenitor star. This process of merging boosts the magnetic field of that star and speeds up its rotation compared to that of the progenitors.

Astronomers say that the newfound tiny white dwarf, named ZTF J1901+1458, took the latter route of evolution; its progenitors merged and produced a white dwarf 1.35 times the mass of our Sun. The white dwarf has an extreme magnetic field almost 1 billion times stronger than our Sun’s and whips around on its axis at a frenzied pace of one revolution every seven minutes (the zippiest white dwarf known, called EPIC 228939929, rotates every 5.3 minutes).

Based on their present understanding of stellar evolution, single white dwarfs do not form from stars with more than 1.3 solar masses. Stars with greater masses instead become neutron stars, or black holes. To get a white dwarf of 1.35 masses thus requires a merger of two white dwarfs, but it also means that the resulting dwarf could be unstable and could collapse into a neutron star at some point. The data also suggests that this merger process might be how a large number of neutron stars actually form.

The dwarf is also the smallest ever found, with a diameter of 2,670 miles, because the larger masses squeezes it into a tighter space.

0 comments

Gravitational wave detectors see two different black holes as they swallowed a neutron star

9:41 am

Astronomers using three different gravitational wave detectors have seen the gravity ripples caused when two different black holes swallowed a nearby neutron star.

The two gravitational-wave events, dubbed GW200105 and GW200115, rippled through detectors only 10 days apart, on January 5, 2020, and January 15, 2020, respectively.

Each merger involved a fairly small black hole (less than 10 Suns in heft) paired with an object between 1½ and 2 solar masses — right in the expected range for neutron stars. Observers caught no glow from the collisions, but given that both crashes happened roughly 900 million light-years away, spotting a flash was improbable, even if one happened — and it likely didn’t: The black holes are large enough that they would have gobbled the neutron stars whole instead of ripping them into bite-size pieces.

Note the time between the detection, in early 2020, and its announcement now, in mid-2021. The data is very complex and filled with a lot of noise, requiring many months of analysis to determine if a detection was made. For example, in a third case one detector was thought to have seen another such merger but scientists remain unsure. It might simply be noise in the system. I point this out to emphasize that thought they are much more confident in these new detections, there remains some uncertainty.

8 comments

Hubble update: Still no solution

2:02 pm

An update today from the engineers trouble-shooting the problem on the Hubble Space Telescope that put it into safe mode on June 13 continue to show the problem is complex, and has not yet been traced to its source.

Additional tests performed on June 23 and 24 included turning on the backup computer for the first time in space. The tests showed that numerous combinations of [a number of] hardware pieces from both the primary and backup payload computer all experienced the same error – commands to write into or read from memory were not successful.

Since it is highly unlikely that all individual hardware elements have a problem, the team is now looking at other hardware as the possible culprit, including the Command Unit/Science Data Formatter (CU/SDF), another module on the SI C&DH [the module that holds the telescope’s computers]. The CU formats and sends commands and data to specific destinations, including the science instruments. The SDF formats the science data from the science instruments for transmission to the ground. The team is also looking at the power regulator to see if possibly the voltages being supplied to hardware are not what they should be. A power regulator ensures a steady constant voltage supply. If the voltage is out of limits, it could cause the problems observed.

They remain hopeful they can find the problem and fix it, though the longer it takes the more worrisome it becomes.

16 comments

Astronomers discover “comet” bigger than the largest comets approaching inner solar system

9:25 am

Astronomers have discovered an object 80 to 100 miles in diameter, larger than the largest comets, approaching the inner solar system and coming from the theorized Oort Cloud of material thought to exist between a tenth and a third of a light year from the Sun.

The object is probably rich in ice like a comet and is currently around three billion kilometres from the Sun. It will reach its closest point, known as perihelion, in 2031. At that time, it will be positioned below the plane of the solar system, near the orbit of Saturn.

Part of the interest in C/2014 UN271 is that it may be something of a transition object. Astronomers believe that many of the long period comets, that occasionally appear with bright tails, actually come from the Oort Cloud. Stars wandering near the Sun can nudge these objects from their positions and over millennia they work their way inwards, with the gravity of the giant planets tweaking their paths on each visit until they reside where we see them today.

“The fact that [C/2014 UN271] has a perihelion so far away from the Sun might be telling us that it’s done this a couple of times but is still in that process of eventually becoming some of those long period comets we know and love,” explains Meg Schwamb a Kuiper Belt and Oort Cloud expert at Queen’s University Belfast.

Initially astronomers thought because of its size that it was not a comet, but new observations have detected the first signs of a coma, suggesting that it will provide us a very interesting and extended show when it reaches its closest point in 2031. Because that perihelion is around the orbit of Saturn, the object will not be traveling very fast, so its passage through the inner solar system will take several years. Its size also suggests it will have a lot of material that can sublimate off to produce a tail.

The object was discovered by two astronomers, Gary Bernstein and Pedro Bernardinelli. If it turns out to be a comet it will then be named Comet Bernardinelli-Bernstein, or Comet B-B for short.

UPDATE: It is official. The object is now officially a comet, and named Comet Bernardinelli-Bernstein.

4 comments

2,000 nearby stars found that see the Earth cross in front of the Sun

9:47 am

Astronomers have identified 2,134 nearby stars that at some point in the past, present, or future are properly positioned along the solar system’s ecliptic so that the Earth can be seen transiting in front of the Sun.

From their paper’s abstract:

[W]e report that 1,715 stars within 100 parsecs from the Sun are in the right position to have spotted life on a transiting Earth since early human civilization (about 5,000 years ago), with an additional 319 stars entering this special vantage point in the next 5,000 years. Among these stars are seven known exoplanet hosts, including Ross-128, which saw Earth transit the Sun in the past, and Teegarden’s Star and Trappist-1, which will start to see it in 29 and 1,642 years, respectively. We found that human-made radio waves have already swept over 75 of the closest stars on our list. [emphasis mine]

I like the detail highlighted. Of the stars that could definitely identify the Earth by transits, 75 are also now close enough to have also heard our radio broadcasts. Should any of those stars also have a sufficiently advanced alien civilization, they could know of our existence. These same stars in turn make for very good targets of study for us to see if there is alien life there.

17 comments

Update on attempts to bring Hubble back to life

4:26 pm

Engineers have released an update on their attempts to bring Hubble out of safe mode that are indicating that they are honing in on the cause of the problem.

After performing tests on several of the computer’s memory modules, the results indicate that a different piece of computer hardware may have caused the problem, with the memory errors being only a symptom. The operations team is investigating whether the Standard Interface (STINT) hardware, which bridges communications between the computer’s Central Processing Module (CPM) and other components, or the CPM itself is responsible for the issue. The team is currently designing tests that will be run in the next few days to attempt to further isolate the problem and identify a potential solution.

This step is important for determining what hardware is still working properly for future reference. If the problem with the payload computer can’t be fixed, the operations team will be prepared to switch to the STINT and CPM hardware onboard the backup payload computer. The team has conducted ground tests and operations procedure reviews to verify all the commanding required to perform that switch on the spacecraft.

It appears that no matter what solution they arrive at, they will still require several days to test the solution to make sure it works. This update however is very hopeful, as it does appear they are locating the cause and have avenues for fixing it.

Hubble went into safe mode on June 13, which means it has now been out of operation for more than ten days.

7 comments

Hubble remains out of commission, with no repair date in sight

9:32 am

According to a statement to Space.com provided by the engineers trying to fix the Hubble Space Telescope, “there is no definitive timeline for bringing the computer back online.”

The Hubble operations team is working to solve the payload computer issue onboard the Hubble Space Telescope. The team is working to collect all the data available to them to isolate the problem and determine the best path forward for bringing the computer back to operations. At this time, there is no definitive timeline for bringing the computer back online. However, the team has multiple options available to them and are working to find the best solution to return the telescope to science operations as soon as possible.

…Assuming that this problem is corrected via one of the many options available to the operations team, Hubble is expected to continue yielding amazing discoveries into the late 2020s or beyond,” the operations team at NASA’s Goddard Space Flight Center in Maryland told Space.com in an email. However, “there is no definitive timeline yet as to when this will be completed, tested and brought back to operational status,

I gather from this that they do have options to might fix the problem, but they have also found the problem to be more complex than expected.

While I honestly am confident these engineers can bring the telescope back to life, we must all be prepared for the strong possibility that this might be the moment when such a repair is impossible. If so, our vision of the heavens will once again be blinded by the poor vision available to us from inside the Earth’s atmosphere. And that vision will not be cleared in the foreseeable future by an American or western optical space telescope, as none are being designed, no less built.

The Chinese however are building one, for their purposes, which will be better than Hubble and is set to launch within the next few years to fly in formation with their new space station, close by so that astronauts can do repairs if necessary.

4 comments
1 … 33 34 35 36 37 … 114