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Messages posted by: wildcard
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Hi Tom,

Thanks for the post and welcome to the forum.

The Argo Navis serial port communication is extremely robust and well tested, so it is most likely to be at the laptop end.

We've tested against Autostar extensively over the years but I just ran Austostar 3.18 on a Windows 2000 machine interfaced to an Argo Navis for half an hour and the connection didn't drop.

Make sure on the Autostar end in the communications dialog that you set parity to none and flow control to none.

I gather from your description the laptop has an in-built DB-9 COM port?

For the cameras drawing power from the USB ports, if the laptop manufacturer had complied with the USB specification, it should be able to
deliver sufficient power to them without interfering with the operation of anything else.

Given it is an older laptop though, is there any indication that is running out of grunt to process the data from the cameras and Autostar?
One test would be to disconnect the cameras and see if there is any improvement to the reliability of the serial comms.

Argo Navis serial ports 1 and 2 are independent and so another test would be to configure SERIAL 1 to run the 'meade' STARTUP command at 9600
and try swapping the cable to it.

Allen Grundmeier wrote:My name is Allen Grundmeier.

I just received my Argo Navis yesterday.
I'm taking it slow to make sure I don't assume that I know where I'm at in the set up process.

This is my question:

I've got a Win 10 computer. I'm trying to find the correct COM port as descriibed on pg (Com & LPT) ports as described on pg 169.

Allen Grundmeier
Robbinsdale, Minnesota

Hi Allen,

Welcome to the forum.

The Keypan USA-19HS comes with a CDROM with software on it. Be sure to install it first before plugging in the USB Serial Adapter for the first time.

The software on the CDROM includes the Window's device driver and a convenient utility called the Keyspan Serial Assistant.

On Windows 10, locate the "This PC" icon on the Deskop, right click on it and select Properties.

A dialog will open. On the left hand side of that dialog select "Device Manager".

Once the Device Manager dialog opens, follow the instructions in the Argo Navis Users Manual and drill down through the Ports (COM & LPT) hierarchy to determine the COM port
number Windows has assigned the Keypsan USB Serial Adapter and to change it to an unused port in the range 1 thru 4 if need be.

Alternatively, click on the Window's Start button on the lower left of the Desktop, left click on it and look for the Keyspan USB Serial Adapter folder.
Within it, select the Keyspan Serial Assistant. When the approval dialog open,s allow it to make changes to your computer. Select the Port Mappings tab and change the COM port that way.

Once you have assigned the USB Serial Adapter an port number of 1 thru 4, when you open the Argonaut software utility, select the corresponding number 1 thru 4 in the Port pulldown.
Then select Connection->Connect.

Hi Mikael,

Thanks for the post and the interesting question.

When the eyepiece is replaced by the much heavier camera, one of three things can happen.

1) The OTA drops in altitude but this drop is reflected by a corresponding change in the altitude encoder values.

2) The top end of the OTA "droops" in altitude as either the truss poles flex, the secondary cage shifts with respect the truss poles or the truss poles shift with respect the split blocks.

3) The camera itself shifts within the eyepiece holder.

I gather from your description you suspect the truss poles flex?

To eliminate 1) as the cause, dial up MODE ENCODER and whilst trying to accidentally nudge the OTA, note whether the altitude encoder values change when replacing the eyepiece with the camera.

Flexure of the truss poles as in 2) is a function of altitude with the maximum flexure occurring when the scope is pointed toward the horizon.
If the flexure is only small, that is within arc minutes, you might get away with a simple linear model.

One approach might be to create a simple TPAS model when the eyepiece is attached. Do a two-star alignment then sample say 6 stars using the SETUP MNT ERRORS functionality.
COMPUTE the model say using only the IE term and apply the model by selecting USE NOW.

When you replace the eyepiece with the camera, using the SET ERROR VALUES, IN USE NOW submenu, you could try changing the INDEX ERROR EL (ID) value to shift the apparent
pointing position in altitude. Perhaps with some trial and error you could ascertain a typical offset.

This approach might also work for 3).

One could also create a more dynamic offset, that is one that is a function of altitude, by creating a model that uses IE, ECEC and ECES, but finding suitable values would be more challenging.

I've never tried this, but the TPAS model and tweaking IE would be my first experiment if it were me. One assumes the shift is systematic rather than a sudden random shift.
I would be interested to hear how you get on.
erick wrote:Just catching up with the posts on this site. Wow Gary! What an experience. Congratulations. Eric

Thanks Eric,

As far as observing locations go, it is absolutely amazing.
Hi Didier,

The ServoCAT definitely won't respond to Meade protocol commands.

You can fill the Argo Navis FROM PLANETARIUM catalog entry either by connecting to the Argo Navis directly using the Meade LX200 protocol
or via the ServoCAT by a program with a servocat driver.

However, to initiate a GOTO from the planetarium, that can only be done by using a program with a servocat driver.

Otherwise if you use the approach where you directly interface to the Argo Navis using the meade protocol, you will need to press the GoTo button on the ServoCAT handpad.
Hi Dave,

One strategy is once you do perform an alignment is to then simply keep the unit powered on.
We have users with fixed observatories that leave their units powered on for days at a time.

Argo Navis allows you to align on any object at any time. You are not restricted to those in the MODE ALIGN STAR list, which is simply a list of convenient bright stars.

You can use the last object you selected in MODE CATALOG, MODE IDENTIFY or MODE TOUR in conjunction with MODE ALIGN (as opposed to MODE ALIGN STAR) to perform an alignment.

This includes a pseudo object whose J2000.0 RA/Dec co-ordinates you have downloaded into the FROM PLANETARIUM entry.

There are several ways to fill the FROM PLANETARIUM entry but for example, if you happened to be running the navis STARTUP command on one of the serial ports
and sent the command :-

fp `STAR1|12:34:56|+12:34|STAR|1.0|MY PLATE SOLVE STAR`

it would fill the FROM PLANETARIUM object with those RA/Dec co-ordinates and if you were then to EXIT out of MODE CATALOG and dial up MODE ALIGN, you could align on it.
Bonjour Didier,

The quick response is that in order to perform GoTo's you will need to interface KStars to the ServoCAT rather than to the Argo Navis.
However, I don't recollect if there is an INDI driver for the ServoCAT using "servocat" protocol and I would need to check.

What happens is that the ServoCAT relays requests for positions and tracking information to the Argo Navis from the PC.
May 29, 2020

Suraiya Farukhi, Ph.D., Universities Space Research Association wrote:
A Steaming Cauldron Follows the Dinosaurs’ Demise

Houston, TX and Columbia, MD—May 29, 2020. A new study reveals the Chicxulub impact crater may have harbored a vast and long-lived hydrothermal system after the catastrophic impact event linked to the extinction of dinosaurs 66 million years ago.

The Chicxulub impact crater, roughly 180 kilometers in diameter, is the best preserved large impact structure on Earth and a target for exploration of several impact-related phenomena. In 2016, a research team supported by the International Ocean Discovery Program and International Continental Scientific Drilling Program drilled into the crater, reaching a depth of 1,335 meters (> 1 kilometer) below the modern-day sea floor. The team recovered rock core samples which can be used to study the thermal and chemical modification of Earth’s crust caused by the impact. The core samples show the crater hosted an extensive hydrothermal system that chemically and mineralogically modified more than 100,000 cubic kilometers of Earth’s crust.

The lead author, Universities Space Research Association’s David Kring at the Lunar and Planetary Institute (LPI), explains,“Imagine an undersea Yellowstone Caldera, but one that is several times larger and produced by the staggering impact event that resulted in the extinction of the dinosaurs.”

The team found evidence that subsurface rivers of water were heated and driven upwards towards the boundary between the floor of the impact crater and the bottom of the Yucatán sea. The hot water streamed around the edges of an approximate 3-kilometer thick pool of impact-generated magma, percolated through fractured rock, and rose to the seafloor where it vented into the sea. The hot water system was particularly intense in an uplifted range of mountains on the seafloor that form a 90 kilometer-diameter ring around the center of the crater. The rock core recovered from that peak ring is cross-cut by fossil hydrothermal conduits that are lined with multi-colored minerals, some, appropriately enough, a fiery red-orange color. Nearly two dozen minerals precipitated from the fluids as they coursed through the rock, replacing the rock’s original minerals.

The peak ring of the crater is composed of fractured granite-like rocks that were uplifted from a depth of approximately 10 kilometers by the impact. Those rocks are covered by porous and permeable impact debris. Both rock units are affected by the hydrothermal system. “Hot-fluid alteration was most vigorous in the permeable impact debris, but garnet crystals, indicating high temperatures, were found at different levels throughout the core,” explains former LPI Postdoctoral Researcher Martin Schmieder who recently assumed a new post at Neu-Ulm University in Germany.

Minerals identified in the new rock core indicate the hydrothermal system was initially very hot with temperatures of 300 to 400 °C. Such high temperatures indicate the system would have taken a long time to cool. The team determined the cooling time using a geomagnetic polarity clock. "Our results indicate that tiny magnetic minerals were created in the Chicxulub crater due to chemical reactions produced by a long-lived hydrothermal system. These minerals appear to have recorded changes in the Earth's magnetic field as they formed. Their magnetic memories suggest that hydrothermal activity within the crater persisted for at least 150,000 years," says co-author Sonia Tikoo from Stanford University.

Further evidence for the hydrothermal system’s longevity comes from an anomalously high concentration of manganese in seafloor sediments, the result of seafloor venting. Co-author Axel Wittmann from Arizona State University explains, “Similar to mid-ocean ridges, venting from marine impact craters generates hydrothermal plumes that contain dissolved and slowly oxidizing manganese, which compared to background concentrations produced enrichments up to ten-fold in post-impact sediments over 2.1 million years at Chicxulub.”

Although the expedition only tapped the hydrothermal system in one location, Kring says,“The results suggest there was an approximately 300 kilometer-long string of hot water vents on the peak ring and additional vents scattered across the crater floor as impact melt cooled. Importantly, such hydrothermal systems may have provided habitats for microbial life.” Yellowstone’s volcanic hydrothermal systems are rich with microbial organisms and imply impact-generated hot water systems have the same biologic potential. Kring concludes, “Our study of the expedition’s rock core from a potential deep Earth habitat provides additional evidence for the impact-origin of life hypothesis. Life may have evolved in an impact crater.”

The extent and longevity of the Chicxulub hydrothermal system suggest that impact-generated systems early in Earth history may have provided niches for life. Thousands of these types of systems were produced during a period of impact bombardment more than 3.8 billion years ago. As each system cooled, it would have provided an environment rich in materials suitable for thermophilic and hyperthermophilic organisms.

Full story, including graphics, here :-

Full paper, "Probing the hydrothermal system of the Chicxulub impact crater" by Kring et. al. :-

Abstract, Kring et. al. wrote:

The ~180-km-diameter Chicxulub peak-ring crater and ~240-km multiring basin, produced by the impact that terminated the Cretaceous, is the largest remaining intact impact basin on Earth. International Ocean Discovery Program (IODP) and International Continental Scientific Drilling Program (ICDP) Expedition 364 drilled to a depth of 1335 m below the sea floor into the peak ring, providing a unique opportunity to study the thermal and chemical modification of Earth’s crust caused by the impact. The recovered core shows the crater hosted a spatially extensive hydrothermal system that chemically and mineralogically modified ~1.4 × 10**5 km**3 of Earth’s crust, a volume more than nine times that of the Yellowstone Caldera system. Initially, high temperatures of 300° to 400°C and an independent geomagnetic polarity clock indicate the hydrothermal system was long lived, in excess of 10**6 years.
May 29, 2020

Chandra X-ray Observatory wrote:
Astronomers have caught a black hole hurling hot material into space at close to the speed of light. This flare-up was captured in a new movie from NASA's Chandra X-ray Observatory.

The black hole and its companion star make up a system called MAXI J1820+070, located in our Galaxy about 10,000 light years from Earth. The black hole in MAXI J1820+070 has a mass about eight times that of the Sun, identifying it as a so-called stellar-mass black hole, formed by the destruction of a massive star. (This is in contrast to supermassive black holes that contain millions or billions of times the Sun's mass.)

The companion star orbiting the black hole has about half the mass of the Sun. The black hole's strong gravity pulls material away from the companion star into an X-ray emitting disk surrounding the black hole.

While some of the hot gas in the disk will cross the "event horizon" (the point of no return) and fall into the black hole, some of it is instead blasted away from the black hole in a pair of short beams of material, or jets. These jets are pointed in opposite directions, launched from outside the event horizon along magnetic field lines. The new footage of this black hole's behavior is based on four observations obtained with Chandra in November 2018 and February, May, and June of 2019, and reported in a paper led by Mathilde Espinasse of the Université de Paris.

Full story, images here :-

Paper at arXiv "Relativistic X-ray jets from the black hole X-ray binary MAXI J1820+070" by Espinasse et. al. :-
Hi Dave,

Thanks for the post.

Sorry to hear things have become more of a physical challenge for you, but great to hear you are determined to solider on.

To help me appreciate the scenario, I gather you can't get up to the eyepiece any more and will be doing imaging through the same camera as well?

Does the scope happen to be permanently set up in an observatory?

I can then put the thinking cap on and see if we can suggest a solution, including possibly feeding back the az/alt to find the alignment stars.

A 16th April 2020 press release by the European Southern observatory (ESO) reports :-

ESO wrote:
Observations made with ESO’s Very Large Telescope (VLT) have revealed for the first time that a star orbiting the supermassive black hole at the centre of the Milky Way moves just as predicted by Einstein’s general theory of relativity. Its orbit is shaped like a rosette and not like an ellipse as predicted by Newton's theory of gravity. This long-sought-after result was made possible by increasingly precise measurements over nearly 30 years, which have enabled scientists to unlock the mysteries of the behemoth lurking at the heart of our galaxy.

“Einstein’s General Relativity predicts that bound orbits of one object around another are not closed, as in Newtonian Gravity, but precess forwards in the plane of motion. This famous effect — first seen in the orbit of the planet Mercury around the Sun — was the first evidence in favour of General Relativity. One hundred years later we have now detected the same effect in the motion of a star orbiting the compact radio source Sagittarius A* at the centre of the Milky Way. This observational breakthrough strengthens the evidence that Sagittarius A* must be a supermassive black hole of 4 million times the mass of the Sun,” says Reinhard Genzel, Director at the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, Germany and the architect of the 30-year-long programme that led to this result.

Located 26 000 light-years from the Sun, Sagittarius A* and the dense cluster of stars around it provide a unique laboratory for testing physics in an otherwise unexplored and extreme regime of gravity. One of these stars, S2, sweeps in towards the supermassive black hole to a closest distance less than 20 billion kilometres (one hundred and twenty times the distance between the Sun and Earth), making it one of the closest stars ever found in orbit around the massive giant. At its closest approach to the black hole, S2 is hurtling through space at almost three percent of the speed of light, completing an orbit once every 16 years. “After following the star in its orbit for over two and a half decades, our exquisite measurements robustly detect S2’s Schwarzschild precession in its path around Sagittarius A*,” says Stefan Gillessen of the MPE, who led the analysis of the measurements published today in the journal Astronomy & Astrophysics.

Most stars and planets have a non-circular orbit and therefore move closer to and further away from the object they are rotating around. S2’s orbit precesses, meaning that the location of its closest point to the supermassive black hole changes with each turn, such that the next orbit is rotated with regard to the previous one, creating a rosette shape. General Relativity provides a precise prediction of how much its orbit changes and the latest measurements from this research exactly match the theory. This effect, known as Schwarzschild precession, had never before been measured for a star around a supermassive black hole.

The study with ESO’s VLT also helps scientists learn more about the vicinity of the supermassive black hole at the centre of our galaxy. “Because the S2 measurements follow General Relativity so well, we can set stringent limits on how much invisible material, such as distributed dark matter or possible smaller black holes, is present around Sagittarius A*. This is of great interest for understanding the formation and evolution of supermassive black holes,” say Guy Perrin and Karine Perraut, the French lead scientists of the project.

This result is the culmination of 27 years of observations of the S2 star using, for the best part of this time, a fleet of instruments at ESO’s VLT, located in the Atacama Desert in Chile. The number of data points marking the star’s position and velocity attests to the thoroughness and accuracy of the new research: the team made over 330 measurements in total, using the GRAVITY, SINFONI and NACO instruments. Because S2 takes years to orbit the supermassive black hole, it was crucial to follow the star for close to three decades, to unravel the intricacies of its orbital movement.

The research was conducted by an international team led by Frank Eisenhauer of the MPE with collaborators from France, Portugal, Germany and ESO. The team make up the GRAVITY collaboration, named after the instrument they developed for the VLT Interferometer, which combines the light of all four 8-metre VLT telescopes into a super-telescope (with a resolution equivalent to that of a telescope 130 metres in diameter). The same team reported in 2018 another effect predicted by General Relativity: they saw the light received from S2 being stretched to longer wavelengths as the star passed close to Sagittarius A*. “Our previous result has shown that the light emitted from the star experiences General Relativity. Now we have shown that the star itself senses the effects of General Relativity,” says Paulo Garcia, a researcher at Portugal’s Centre for Astrophysics and Gravitation and one of the lead scientists of the GRAVITY project.

With ESO’s upcoming Extremely Large Telescope, the team believes that they would be able to see much fainter stars orbiting even closer to the supermassive black hole. “If we are lucky, we might capture stars close enough that they actually feel the rotation, the spin, of the black hole,” says Andreas Eckart from Cologne University, another of the lead scientists of the project. This would mean astronomers would be able to measure the two quantities, spin and mass, that characterise Sagittarius A* and define space and time around it. “That would be again a completely different level of testing relativity," says Eckart.

Press release including artist impression here :-

JohntheLast wrote:That was the conclusion that I was coming too. Obvious, once you think about it. I didn't see any reference in the manual (but I may have missed it). If it's not there, perhaps a point should be made (even if obvious) that if you are using a Servocat you may have to disconnect the Serial 1 cable that goes to the Servocat and temporarily replace it with a direct connection to the PC.

BTW, you'll find an order in your stack for the serial cable.

Thanks again for the quick response and help. Your product has made the difference between being able to observe and just sit on the sidelines. I live in a very light polluted area and the ability to GOTO and Tour with the capability that you provide makes the difference between being a participant and being a by stander.

Your Argo Navis Serial Cable shipped by Economy Airmail earlier today.

Good to see you probably tumbled as to the requirement for a direct connection between the Argo Navis and PC when I mentioned
you explicitly need to use the Argo Navis Serial Cable which is different to the ServoCAT Cable.

You may not have been the first to try it via the ServoCAT but you are definitely the first I am aware of from a support perspective,
so it has provided me with another question to ask people and the prompt to add an additional line of text to the User Manual. smilie

Hopefully once your Serial Cable it will all go smoothly.

Thank you for the additional anecdote on how using your Argo Navis is a gamechanger under light-polluted skies. That's really wonderful to hear.

Clear skies!

JohntheLast wrote:This may be a stupid question but in the Servocat configuration the Serial 1 port on the argonavis is connected to the DSC port on the Servocat. The Servocat USB port is then connected to the USB port on the PC. That would tell me that there is no direct connection between the argonavis and the PC (although there may be an internal pass through on the Servocat).

For the upgrade process, does the argonavis Serial 1 port have to be directly connected to the PC (i.e. not go through the Servocat)?

There is never a stupid question here smilie

When you have that daisy chain of PC <-> ServoCAT <-> Argo Navis, there is no direct connection between the PC and the Argo Navis.
What happens is that the ServoCAT relays requests and responses onto and back from the Argo Navis. So for example, Argo Navis is
responsible for performing all the object offset and tracking rate calculations on behalf of the ServoCAT and that dialog takes place
just between the two of them. Now and then the PC might request where we are at in terms of RA/Dec coordinates and the ServoCAT
relays that request onto the Argo Navis and it then relays the response back to the PC.

For the upgrade process, the Argo Navis must be directly interfaced to the PC.

If the ServoCAT were to see the Argo Navis firmware data, it would not be able to make head or tail of it.

Hence you must use the Argo Navis to PC Serial Cable in conjunction with the USB Serial Adapter. The Argo Navis to ServoCAT cable is wired
completely differently.
JohntheLast wrote:Am I also interpreting the baud rates correctly.

The Baud rate for the Serial 1 to DSC interface on the Servocat should be 19200 and the USB/COM4 interface should be 38400?

When you power up the unit in normal mode, the serial port protocols and Baud rates are determined by whatever they are set to in the SETUP SERIIAL menu.

For interfacing to a ServoCAT the setting is BAUD=19200 STARTUP=servocat

If you wanted to run the check for the % prompt as detailed in the Establishing Communication section of the User Manual,
set the port being interfaced to the PC with a BAUD=38400 and STARTUP=navis.

Whenever you change the STARTUP command, press ENTER or EXIT to make the change and then power the unit OFF and ON to make the new STARTUP protocol to start.

When in BOOT LOADER mode, the settings in SETUP SERIAL are no longer applicable. The only serial port that is then operationally valid is SERIAL1.
It's Baud rate is fixed at 38400. This therefore is the Baud rate at which firmware upgrades take place.

Argonaut works with all versions of Windows including Windows 10.

The USB Serial Adapter we recommend is the Keyspan USA-19HS.

Some have success with adapters using the FTDI chipset but the correct driver is crucial.
Brand of USB Serial Adapter?

Had you successfully communicated with your Argo Navis using it before, or is this the first time you have used this combination?

Get some sleep and we are here to assist when the time comes. smilie
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