Wednesday, October 25, 2017

Focus Issue Resolved

Jonathan Green, got out to Kumeu Observatory last week in an attempt to resolve the focus issues he reported last time he and Shaun Fletcher were out there, after consulting Grant Christie about the issue he came armed with some new settings to try, once he had inputted the new settings the TCF auto-focus worked and the camera didn't stop anymore although he still couldn't run through a v-curve due to not having enough steps to get through, in other words the auto-focus was hitting the step number 1 before completing the v-curve, so knowing that the solution for that is to set the TCF back to 3500 which is the halfway point and then manually focus the telescope until it's back to near focus, once that was completed getting the v-curve was simple and getting a decent focus was not a problem.

Of course to manually focus the telescope he had to un-lock the primary mirror so we will probably need to re-collimate the telescope, also by moving the mirror this has also shifted the T-Point model so we will need to do another pointing model as well, knowing that we also need to take the camera off the telescope to remove the old Wratten and luminance filters and replace them with the new filters provided to us from Astronz Jonathan decided to not attempt another T-Point model until the new filters had been installed, of course there was also plenty of clouds around on the night that also influenced his decision to not attempt a new pointing model as well.

Unfortunately Jonathan discovered a new issue on the night with our computer network, the computer downstairs won't communicate with the dome PC anymore or go online, so we can't currently check the cloud sensor online at the moment, Steve Hennerley is back from overseas now so after having a chat with him over the phone we diagnosed the problem and Steve is going to purchase the replacement parts to get the network back up and running.

Now that Steve is back in New Zealand we are going to spend some time this Spring / Summer really optimizing all our systems at the observatory including our Polar Alignment, the tracking speed of the mount, collimation and a few other jobs that we were putting off while the microlensing season was still underway, we also have been granted a budget from the council of the Auckland Astronomical Society to employ our observatory neighbour Peter McLeod to undertake repairs to the dome's base ring and skirting as well as cleaning and re-painting the dome, we get our mains power from Peters house so it's great that we have someone so close to us that is prepared to undertake all the work that needs to be done to restore the observatory to it's former glory, again a huge debt of thanks is owed to Steve Calveley for suggesting to us that Peter could do all the work that was needed and of course for letting us operate the Kumeu Observatory on his land.


<- As you can see from this photo of a Moon halo above the Kumeu Observatory, the dome is really in dire need of a good clean and re-paint!



Posted by Jonathan Green

Wednesday, September 20, 2017

Focus Issues

Last night was the 1st good night in a while so Jonathan Green and Shaun Fletcher headed out to Kumeu so Shaun could get some practice in, unfortunately we had an issue with the Optec TCF focuser, basically it would start the auto-focus run take one or two images and then just inexplicably stop, also at times it would try to move the focus to some crazy step number size like around the 200,000 mark when the maximum step size is of course just 7,000, I was at a loss to explain this strange behaviour as no settings have been changed in the downtime between clear skies and it was working perfectly fine the last time I was out there, so we tried shutting everything down a number of times to see if maybe we had done something wrong in the setup procedure but nothing seemed to work and we were hit with the same problem every time we got to the auto-focus process, thankfully we have an Auckland Astronomical Society council meeting tonight so I'll be able to ask Grant Christie about the problem and see if it can be resolved, I'm sure it must be something simple that is just eluding me at the moment.

Last night we also had a few visitors to the Observatory we had a local Kumeu astrophotographer who is just 16 years old come and take a small tour of the Observatory with his Dad, we encouraged them to join the society and to visit Stardome where they will be able to actually "look" through a telescope, we also had two society members use the observatory grounds as a dark site to do some deep sky astrophotography from, so it was a busy night out at the observatory indeed! Even though it was really a very frustrating night for myself.


<- Robert Patterson setting up his imaging rig

Posted by Jonathan Green

Monday, August 28, 2017

And Then There Were Three

Last week and over the weekend we had a couple of good nights, so with no current alerts on, Jonathan took the opportunity to complete Shaun Fletcher's training, now there are three people who are capable of operating the setup in the main dome of Kumeu Observatory, we will still be looking to train more members of the Auckland Astronomical Society so that we can ensure that the observatory will never become disused and derelict again.

Speaking about derelict, Jonathan Green also met up with the treasurer of the society Niven Brown on Sunday afternoon to show him the damage to the dome that Steve Hennerley had discovered before he went overseas, basically we have a bit of rot on one side of the dome, probably because the skirting was never replaced and is inadequate to protect the under side of the dome from the elements, David Moorhouse had mentioned this problem to Bill Thomas last time he saw him in the city, Niven took some photos of the damage and will circulate them to the council, so hopefully with the consent of the council we will be able to hire a builder to come fix the problem, we also want to get the dome cleaned up as well seeing as it looks quite grubby with loads of moss and mold on the outside of the dome, it will probably need treating with a chemical wash and perhaps could be re-painted afterwards as well.


< Screen shot of an image of the Trifid Nebula that I'm working on in PixInsight, I'm still learning how to use PixInsight but it's a fantastic program and I can really see why Rolf Wahl Olsen gets such great results using it.

Posted by Jonathan Green

Saturday, August 5, 2017

Internet and a Few Good Nights.

Sorry for the lack of updates, since you last heard from us, we now have the internet out at Kumeu Observatory thanks to Steve Hennerley, we also had a number of good nights last weekend, we didn't have any current Microlensing alerts on, so Jonathan invited Auckland Astronomical society members Shaun Fletcher and Carolle Varughese over to learn the basics of MaxIm DL, Shaun having his own home observatory and being an Astrophotographer picked it up really quickly and Carolle having studied Astronomy and having done a years worth of observations at Mt John Observatory also picked it up quickly, so we probably only need a few more nights of training to get these two up to speed, with no current Microlensing events to follow we do need to start thinking about new projects to tackle.

Another issue that has been discovered with the amount use of the dome is now getting is that the fibreglass sides are starting to really degrade and will require some maintenance, we will be bringing this up at the next society council meeting to hopefully devise a plan of action to repair the dome and perhaps even get the dome cleaned and painted at the same time as it's quite grubby after all these years.


<- M8 The Lagoon nebula captured and processed by Shaun Fletcher at Kumeu Observatory.



Posted by Jonathan Green

Friday, July 21, 2017

Crisis.....Averted... (but a lost night...)

On Tuesday 18th July, Jonathan headed out to the observatory to find beautifully clear skies perfect for some follow up imaging.  After getting set up and ready to grab some data, the remote connection to the dome PC from the bunkroom suddenly failed.  Checking upstairs the dome PC was no longer powered up - and - even worse, wouldn't actually power up.

Even the IT support favourite advice of "turn it off and turn it on again" (well unplug it completely) did not manage to solve the issue.  Unable to contact Steve initially, Jonathan headed out to make the most of the clear skies with some DSLR astrophotography.

The following night Jonathan and Steve managed to hurry along the Auckland Astronomical Society council meeting members with a view to getting out of the meeting and up to the observatory as quickly as possible - with a spare computer power supply in hand.

Almost as expected (remember Murphy?).. the PC powered up instantly...

The challenge was working out WHY the PC had failed because having unreliable equipment is certainly going to have a negative effect on our efforts.  Out came the power supply tester (Steve's a professional IT nerd so has these things lying around...) and everything looked good... fearing the worst... the "intermittent problem"... Steve reconnected everything and powered up again to start some additional diagnostics.

One common cause in the PC world when something goes off suddenly and won't power back up (even with a "power cycle") - but then does some time later (maybe many minutes later) - is that there has  been a short circuit, power surge or "overcurrent" problem somewhere on the motherboard or power supply.  Most IT techs have seen this most often when an errant screw accidentally makes its way (purely by itself you understand) onto the exposed boards of a PC.  The protection circuity (such as polyfuses) kick in and power is removed.  It is common not to instantly come back on when the fault is removed.
OB171186_170719

The hunt was on - for insects in the power supply, "errant screws", possibilities of electrical surge (though the surge protector was still functioning).  Nothing was obvious ... so case back on and stand the PC back up.

At that point the probably cause of the issue was suddenly staring us in the face... the bright blue power LED (which is normally covered loosely with black electrical tape) was off... whilst the PC was on.  Jonathan was certain the light was on the night before when he was setting up and checking inside again, it was still connected.

It seems likely that the blue LED had failed, which in turn had tripped protective circuitry on either the motherboard or the power supply.  The mystery solved, we could be a lot more confident it wasn't going to happen again, and we took the opportunity to do something that should have been done when Steve built the PC - disconnect the Hard Disk and  power lights completely to protect the darkness of the dome.

With that resolved, and the skies clearing, Jonathan and Steve set out to grab some images of a new high priority microlens target OB171186.  Joanathan managed to get 28 300 second images over the next couple of hours - though had a few problems - the strange and as yet undiagnosed mount disconnection (from an earlier blog post) and an issue plate solving a number of (most of) the images in PinPoint.

Light Curve from OB171186
Steve processed the images next day for upload and managed to get the astrometric solution by reducing the number of star used for the solve and also narrowing the intensity range used for matching in the PinPoint settings.  This seemed to do the trick.  Steve also ran the images through a tool called PySIS - which uses differential image analysis to generate a photometric light curve.

Posted by Steve Hennerley




Monday, July 17, 2017

Action Stations!

OB171317
On Saturday the 15th of July Jonathan Green and Steve Hennerley were at Kumeu Observatory, after some advice from Grant Christie that the microlensing target OB170019 was still viable, we took just over an hour's worth of data on the target, Grant had advised that we didn't really need any more than an hour so we were kind of stuck for new projects as there had been now new microlensing alerts for a while, that day Jonathan Green had signed up for the Center for Backyard Astrophysics (CBA) in the hopes of finding some more projects to take on, he had copied down a few Cataclysmic Variable targets to attempt to image, so we attempted a few of the targets but found that each of them was only just above the noise level, so not knowing if that would be useful or not we decided to take more images of OB170019, unfortunately the clouds started rolling in about this time and we couldn't guide for 5 minutes anymore so we decided to pull the plug on the night and headed home with the idea of doing some research and finding some new projects to pursue when we don't have any more microlensing work to do.

On Sunday the 16th of July we finally had a new microlensing alert so it was action stations! Only one problem the forecast for that night was for increasing clouds! We decided to give it a go anyway and just hope for the best, Steve arrived 1st and found the sky was half clear and thankfully our target was on the clear side, so he opened up the dome and got to work, he captured 14 300 second exposures of our target OB171317 before Jonathan arrived, after a few cloudy patches we got back to work but it was slow going with passing clouds causing our guide star to fade more often than not, Steve headed home and Jonathan stayed on to keep imaging for as long as possible, we got to 27 300 second exposures of our target OB171317 although thin clouds may have affected a few of them.
Jonthan imaged the target when gaps allowed until 1:30 am when this cloud bank appeared in the West, it didn't take long after this photo was snapped for the cloud bank to move over our target and even though Jonathan stayed on at the observatory until around 3 am he never saw another opportunity to collect more data, so after calibrating the data we had collected he headed home and sent the files to Steve for submission to MicroFUN, hopefully we get a few more breaks in the clouds tonight to grab our normalizing data as apparently our target has already faded considerably.


Posted by Jonathan Green

Tuesday, July 11, 2017

Cloudy Nights at Kumeu

Since the last night imaging at Kumeu, we have had a run of some really bad weather, on Sunday the 9th after attending Neil deGrasse Tyson at Spark Arena I headed out to the observatory in the hope of clear skies but even with other parts of Auckland clear Kumeu was still under a pretty constant blanket of clouds, after waiting I drove home to find Coatesville clear but you could still see major clouds in the West. On Monday the 10th after attending the Auckland Astronomical Society meeting I headed out again in the hope of clear skies but it was raining on arrival so I attempted to wait out the clouds and rain by occupying myself with cleaning up the observatory but with no luck it was still heavy cloud when I left around midnight, I'm happy to report we have submitted all our current data to MicroFUN so all we need now is some clear sky to get back to work although fortunately there has been no new microlensing alerts in the meantime.


^ As you can see from this image of the cloud sensor graph clear patches have been few and far between, it's been frustrating because other parts of Auckland have looked relatively clear.

Posted by Jonathan Green

Tuesday, July 4, 2017

A Night of Two Halves

On Monday the 3rd of July, Jonathan Green decided to miss going to the Auckland Astronomical society meeting and head out to Kumeu instead, after a weekend of rain and clouds it looked like things were finally clearing up, after arriving around 6:15pm he opened up the dome setup and got a focus of a FWHM of 1.7 arc seconds per pixel ( not bad for having only just opened the dome ), he then got onto taking the normalisation data that we need to submit our latest microlensing data sets, so he started by imaging Ogle-Bulge-2017-1161, which was the priority target, he managed almost three hours worth of data before hitting the hard stop before the meridian crossing, this was the first time he had let the mount hit the hard stop, it made a beeping sound and he found when he tried to send it home that somehow the computer had lost communication with the mount.

OB171161_170703
Fortunately it was precisely at this moment that Steve Hennerley turned up, we resolved the issue with the mount and a few other issues we were having before getting back onto our target, we finished imaging Ogle-Bulge-2017-1161 after collecting three hours worth of data so hopefully that will be enough for normalisation, Steve headed home around 1 am and Jonathan stayed behind to continue imaging, he got started on the Ogle-Bulge-2017-1135 target, the first half an hour was plain sailing but the next 8 300 second images he took, took Jonathan until just after 3 am to grab, that was because we had big clouds coming in, he had to close the dome a few times out of fear of a downpour, the wind had also picked up by this stage so he could only grab one or two images in the brief gaps, after 3 am the situation deteriorated so he packed up and headed home around 3:40 am, so we only ended up getting just over an hours worth of normalisation data on the Ogle-Bulge-2017-1135 target so I'm not sure if that will be enough, after Jonathan made it home he sent all the calibrated image data to Steve Hennerley via the We-Transfer file transfer service to be prepared for submission to MicroFUN.

Obviously there has been a lot of rain over the weekend and things are starting to get a bit more muddy outside the observatory, it was really wet on the night as well with the humidity at a 93% level, Jonathan was very happy to see that at the end of the night we didn't have any sign of dew on our corrector plate so he thinks that the dew shield has proven to be the only thing we really need to keep the dew off, this is just as well because when you have to run the dew strap heater this adversely effects the images.


^Looking down the dew shield at a clean corrector plate after a nights observing in 93% humidity, note also how well baffled the dew shield is, David Moorhouse really did a fantastic job constructing this dew shield!

Posted by Jonathan Green

Saturday, July 1, 2017

A Perfect Winters Night

On Thursday the 26th of June, Jonathan Green headed out to Kumeu Observatory early so he could grab more flat field calibration image files, before he left home he had copied the coordinates of the latest microlensing targets, after taking the flats he checked where the targets were located, only to find they were all still below the tree line so instead of wasting time waiting for them to rise he slewed to the star cluster Westerlund 2 and grabbed 20 x 100 second exposures, by the time that was done the galactic bulge had cleared the trees so he then immediately set about collecting microlensing data, but before he got started he re-focused the imaging system to a FWHM of 1.5 arc seconds per pixel on a magnitude 8.6 star, Jonathan imaged the target OGLE-2017-BLG-1135 until he hit the meridian, he was joined out at the observatory by Steve Hennerley just after 10 pm, while waiting for our targets to pass the meridian Steve and Jonathan used the break to find our target stars we were a little bit concerned that the signal we were recording wasn't strong enough but after a quick phone call to Grant Christie he assured us that our images would provide useful photometry, Steve ended up heading home around 1 am with the understanding that Jonathan would send him all the calibrated data from the night to be readied for submission, I think this is a method that we will employ from now on, after a full nights imaging you feel really tired and that's when mistakes happen so best to have someone who is fresh in the morning to go over the data and make sure it's all sent off correctly, although Steve also showed Jonathan how to prepare the data for submission just in case he ever needs to do it himself.


After preforming the meridian flip we changed targets to OGLE-2017-BLG-1161 as Grant had mentioned that this was the priority target, we ended up getting 34 x 500 second exposures of this target before it got into the fog and mist of the western horizon, we got 32 x 500 second exposures of the OGLE-2017-BLG-1135 target and we also managed to grab 8 x 500 second exposures of OGLE-2017-BLG-0019, one thing I noticed over the night was that some images would not automatically solve in PinPoint so I think we might need to adjust our settings in PinPoint when solving images in the bulge, by 5am I was losing my guide star due to the mist and clouds that were hanging around low in the West, so this was a natural stopping point for the nights imaging. I calibrated all our data and copied it onto a USB data stick, shut down the dome and headed home around 5:30am, when I got home I immediately copied the data onto my computer and sent the files to Steve via the We-Transfer file transfer service, all in all it was a very productive night and I was happy to see when I woke up an e-mail from Grant saying that he had no problem running our images of OGLE-2017-BLG-1161 through Pysis and that the photometry looked good, we are now looking forward to the next clear night so that we can capture the normalisation data for our new targets.


<- The Galactic Bulge not long before Jonathan stopped for the night, thin clouds and fog made auto-guiding impossible and with not being able to auto-guide he couldn't continue capturing 300 second exposures anymore, so this became a natural stopping point.

Posted By Jonathan Green

Wednesday, June 28, 2017

A half decent night finally.

OB170019_170627
On the 27th of June Jonathan Green headed out to Kumeu Observatory at 7:30 pm, there was still a lot of thin clouds about on arrival but the forecast looked pretty promising so he opened the dome and setup for a nights worth of imaging, he targeted OGLE-2017-BLG-0019 to be able to capture some normalising data that is needed to be able to submit our data, he found he could still auto guide through the clouds without too much issue, we only lost the guide star twice over the 1st half of the night.


The Sky conditions looking towards the Galactic bulge for the 1st half of the night. 
Just after 10 pm Steve Hennerley turned up and after a brief chat we decided to just keep imaging the microlensing target OGLE-2017-BLG-0019 for the entire night, we continued imaging without any issues until we hit the Meridian crossing, so we paused to wait for our target to cross the Meridian before preforming a "Meridian Flip", we took the chance while we had a break in the action to fix up the dual monitors of the downstairs computer workstation and then refocused on a mag 8.3 star and got a result of a FWHM of 1.5 arc seconds per pixel, my initial focus was only 1.9 so obviously the "seeing" must have improved, I went out side and found that almost all the clouds had dispersed, Steve needed to go to work early so he hung around to make sure the 1st couple of images came down successfully then headed home, Jonathan Green stayed on imaging until 4:46 am by which stage the target was getting pretty low in the sky in the West, he could tell the images were getting worse at this point and could see via the fits header that he was imaging through an Airmass of 1.8, we had captured 78 x 300 second images of the target so we have plenty of data now, of course our next goal is to actually submit our data, after Jonathan closed up the dome he headed home around 5:30 am.

Posted by Jonathan Green

Tuesday, June 27, 2017

Cloudy nights and a Rookie Mistake.

On the 25th of June Jonathan Green was involved in an astronomical outreach event at Smales Farm on the North shore, the event was a Matariki festival and members of the Auckland Astronomical Society provided telescope viewing to the public, we were ducking rain showers for most of the night but by 9 pm things had cleared up so sensing an opportunity I packed up and left the festival around 9:30 pm to head out to Kumeu, we have had a really bad run of weather lately so you really just have to take your chances when heading out to the observatory at the moment, the sky was still clear when I arrived but after I had opened up the dome and managed to get a decent focus heavy clouds began to roll in, I went outside and watched them for a while, the clouds became progressively thicker and the wind started to pick up, I was lucky to just beat a really heavy rain shower by racing up and closing the dome just in time, I attempted to wait out the clouds and rain by occupying myself with cleaning up the observatory and cleaning up the dew shield that David Moorhouse had built for the "Nustrini" C14, spiders had built lots of webs in it since we took it off when installing the Paramount GT100S, after I had done all that I found that it was still raining and with no gaps on the horizon I decided to head home around midnight.


^ Jonathan Green Shows a member of the public Jupiter through his 8' Meade LX90 SCT.

On the 26th of June Jonathan Green headed out to Kumeu Observatory at 7 pm in the hope of finally capturing some clear skies unfortunately the sky was completely clouded out when he arrived, the forecast was for a clear skies for the following day so in the hope the skies would clear sometime over the night he setup the newly cleaned dew shield onto the "Nustrini" C14 and opened up the dome, while waiting Alan Kane turned up also with the idea of doing some observing, I talked to Alan about the cloud sensor and how it was no longer logging data on the graph and he showed me how to reset it, so our cloud sensor is back to working properly again which I'm really happy about, by the time Alan had set up his Dobsonian the sky started to have a few gaps in the clouds, so I set about gaining focus, after many attempts the best I could manage was a FWHM of 2.5 arc seconds per pixel, not good at all compared to the other night, Alan also confirmed that the seeing looked average visually.


The clouds were coming and going so I attempted to get some work done in the odd gaps, what I wanted to do was take an hour or two of normalising data on the previous microlensing target that we got data on the last time it was clear, because you can't submit your data without the normalising data, I did manage to capture an hours worth of data but I was really not happy with the quality of the images even though I didn't have the dew strap on at all thanks to using the dew shield, using the graph window in MaxIm DL I could also see that the results were really jumping around, I went outside to talk to Alan about the sky conditions and he confirmed that even in the clear gaps we were still getting mist and thin clouds so this was no doubt what was causing the results to jump around, around 11 pm I had to stop due to deteriorating conditions, I went to calibrate all the data I had captured on the night so far only to find I had made a rookie mistake, all the data I had captured on the night was at 2x2 binning but we only have full calibration files for 1x1 binning, I guess my mind was a bit distracted as my e-mail accounts had been hacked that day and I was still getting phone calls about it while I was at the observatory, I just didn't notice that the binning was at 2x2 not 1x1, it was a painful lesson to learn as it meant the nights observations were useless but I know I won't be making that mistake again ( I hope ), on a positive note the dew shield worked perfectly, so I think we will be keeping that on the telescope from now on, by 11:30 pm the sky conditions had really become quite bad so Alan packed up and headed home, while Alan was packing up I managed to focus a star at a FWHM of 1.7 arc seconds per pixel during a break in the clouds, so not wanting to go home while I had a finally managed to get a half decent focus I stayed on, unfortunately the sky conditions just worsened so I ended up giving up around 2 am and packed down and headed home in defeat, hopefully the sky will be clear tonight so I can finally get the normalising data I need to start submitting microlensing data.


^ David Moorhouse's well constructed dew shield on the "Nustrini" C14

Posted by Jonathan Green

Monday, June 19, 2017

Sharp Focus on a Marginal Night!

Saturday the 17th of June was a fantastic Winters day with lovely blue skies, unfortunately as the Sun began to set thin clouds started to roll in, thinking that I may as well head out to Kumeu anyway in the hope that the clouds would clear up I arrived at the observatory at 7:30 pm, the Sky was certainly not clear on arrival, so I just opened up the dome and hoped that things would improve, while waiting for the sky to clear I noticed that the cloud sensor was no longer logging data, I'm not sure what the problem is, after giving Steve a call, I tried a few things but failed to get it working again, so that will be something we will need to have a look at, as having a working cloud sensor is very useful indeed.


<- The Sharpest Focus ever recorded at Kumeu Observatory so far!


I noticed that the one part of the Sky that seemed not to have many clouds, was looking in the direction of the constellation of Carina, so knowing that there is an interesting target in that part of the sky, I set about gaining focus, It was a bit strange that on a night when the conditions were so marginal I managed to get the sharpest focus ever obtained from Kumeu Observatory! With a FWHM of 1.25 arc seconds per pixel on a Mag 8.6 star! We have discovered evidence that we have mirror flop issues so maybe the mirror just flopped into perfect collimation or something?


After gaining a sharp focus I started to image the Star Cluster Westerlund 2, the cluster contains some of the most massive stars known in our galaxy as well as many interesting "Wolf–Rayet stars", even though that part of the sky was the clearest, I think there was still enough clouds around to end up effecting the images so I'm not sure if the data will be useful or not but Grant Christie and Tim Natusch at Stardome Observatory have been studying the cluster for a while now so they might find the data useful.



^ A stack of an hours worth of one minute exposures of the Star Cluster Westerlund 2 in the constellation of Carina.

By the time I finished the hour long run on Westerlund 2 I set about attempting to gain some data on our current microlensing targets but needing to get five minute exposures I found I couldn't autoguide for long before losing the guide star due to clouds, so after a few attempts I went outside and found that the sky conditions had deteriorated, so I packing down and headed home just after midnight.


<- The Sky Conditions when I arrived at Kumeu Observatory.



Posted by Jonathan Green

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