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Oc-folks: Just quickly... Whilst making up plans for tonight I ran across a good example of why it's nice to input the Lat & Long of other's sites into Occult4. (I can explain how to do this in a later chat). In short, in the 2 attached images you can see the sites of other NEUS observers (the "dots"), and when the path is plotted it becomes instantly obvious if the path you are considering passes by anyone else. Here you can see an event I was considering also passes near Steve C and Michel M. If set up correctly you can even access Google Earth from Occult4 and zoom in (way in!) to see how close a path actually runs. BTW, this event is a bit too faint (maybe?) - 15.5 combined, Max dur of 1.06 sec. Steve -- I'll be responding to your "Thoughts?" post.... when I have spare moment. Now back to tonight's planning. (Got 1 Pos last night). George

Our tests with our 12" Skywatcher have yet to be successful. I will be picking up my Astrid tomorrow, Saturday, so maybe that will help. One issue we've had is that the scope gets out of collimation when travelling. Two questions: (1) How do you keep the vibrations low when in transit so the mirrors stay aligned? (2) Is there a preferred collimator? I clearly need to get one.

Is anyone uploading their lightcurves to Occult? I found the instructions in the Help area confusing--any hints at best practices in doing this? Thanks. Steve

Some: Yes, some.... This presentation may not interest most, tho maybe some... We recently had a seemingly constructive 2-hour Zoom session where we discussed getting 'new' folks involved in observing occultations. Yes, it would (certainly) be great to get a few more chords in the Northeast(!). But I think we agreed we tend to run into a stumbling block when it comes to finding an easy way for them to get started in actually timing events. Frankly it's often a notable financial outlay in the order of several hundred dollars for someone who thinks they **might** be interested, to get started. Yes, some have ample "disposable income", but many don't. For those who's pockets aren't stuffed with cash, I think this becomes a reason for them to perhaps think otherwise about getting involved. So.... I've mentioned flash timers. ...And please, I want to make it very, very clear, I do not believe they are by any means an ideal way to time occultations. However under certain circumstances they can serve a useful purpose. I see flash timers having value in two main instances: * For beginners to get STARTED - and.... * As a backup timing device [...And possibly in other "special instances"] There have existed two "flavors" of flash timers: * Flashers which reference GPS time signals - like those designed by Aart Olson, and based on an Arduino architecture - and... * Flashers which use the camera flash on a smart phone, and use NTP (Network Time Protocol) as their time base I 'own', and have run tests on both of the above types. Currently there seem to be no readily available, "purchase-able", units along the lines of "Aarts GPS Flasher". And to make one requires some skill in electronics assembly, with parts probably costing several hundred dollars. In contrast, there has existed a flasher of the second type (NTP-based), which was once available as a free downloadable app for smart phones. I am referring to the app called "Occult Flash Tag" (herein, "OFT") - once available on Google Play and installable on Android smart phones. (As of this writing, Google Play does not offer this app, but it may again in the future). One nice thing about OFT is/was that if a "beginner" already owns a video-capable astro-camera, and happens to have an Android smart phone in their back pocket, they could conceivably have everything they need to start timing occultations(!). But more toward the point of this post... Many "occultationists" have voiced notable reservation in basing timings on NTP. I completely agree that GPS-based timing methods should in theory have the edge over NTP. But in actual tests, just how well does and NTP (ie., OFT) perform? I've had version 1.1 of OFT on my Android smart phone for several years now. Several years ago I ran tests at the telescope where I simulated short occultations. On each video, I had both timestamps from an IOTA-VTI, and flash markers. Recently I re-ran tests on several different nights where I again simulated an occultation, and this time each video frame was timestamped by my Astrid camera, and I also placed OFT flasher markers on the same video. All together, over the years years, I've analyzed about 45 video tests (in all tests the recorded video indicated NO timestamp errors). In short, in every test (most all done at 30fps), when D & R times derived from the timestamps were compared to D & R times derived from OFT, the agreement was within a small fraction of the exposure time of each frame. No tests had errors greater than 0.033 seconds (1 frame of standard NTSC video). So below is just an FYI post of recent comparative results... And you can draw any conclusion you wish. The attached images represent 13 out of 13 recent tests I've done (it's easier that I just scan the written pages of test results). Note: OFT has several different accuracy level settings, and for these tests it was set on the "very high accuracy" setting. Really all that needs to be looked at are the comparative times in the yellow boxes. In short, the average deviation in time between timestamping and OFT's derived time is 0.0108

Everyone, The first flasher box is done (again!)--photo attached. We had issues getting it to use its SD card due to a change that Adafruit made to their GPS board last summer. Aart and I went back and forth quite a bit trying to get mine working. In the end, Aart bought one of the new boards (he only had some of the older versions before this--and be warned there are several--maybe four--versions with the same name if you find an old one kicking around your junk drawer) and got it going. Once he shared the recipe which only required a software change, I had mine working in a couple of minutes. Testing is next when I have some time. I did find in my junk draw one of the older Adafruit boards--which was also different from all the ones Aart had. He is pretty sure he knows how to set my old one up, and sent me a "sketch" (Arduino program) that should drive that one. I bought a cheap clone Arduino Mega ($22) for that one and plan to put it together and print a box for it this week--I have spare parts from the first as most of the smalls (connectors, LEDs, etc) came in 10 or more packs to use. Again, if anyone wants one, I can put one together for you and send it in your direction for cost of the parts--of order $50 to $80 plus shipping depending on what Arduino board you want. Steve

After our discussion last night, I've decided to build one of Aart's flash timers. Reasons for doing this: So we will have knowledge of the cost and amount of effort it takes to put one together, to be able to tell anyone we are recruiting To allow me to learn how "difficult" they are to use, again to be able to tell a new recruit To be a loaner we can send to new folks starting out To allow me to try the IMX432-sensored Player One camera I now have, as the large 9 um pixels are better matched to my C14 and might allow me to get to fainter events (really purchased for my spectrometer to get more sensitivity in blue) Looking through my astronomy junk drawer, I found an attempt at a flash timer I made many years back. It consists of an Arduino Uno, Adafruit Ultimate GPS shield (with an IC, resistors, and jumpers I added), and a 2x16 LCD display shield. I may also try to resurrect that if useable. Aart has quite a number of designs in his folder in the IOTA groups.io files section. I've emailed him to ask which he'd recommend for a beginner (for both ease of assembly and use). Steve

Once again, another very nice event - and it's nowhere to be found on either OW Desktop or OW Cloud. Here's another example of why it pays to run your own searches using Occult4. Many events now (springtime) are quite low on the horizon (roughly... the star-rich region of Gemini is low in the west, Sagittarius is low to the south-east or south...). Many events are simply "tough", and the short nights don't help. Low and behold, I do an Occult4 search for May 21st UT and find an event involving a 10.1 mag star, and 43 degrees up (in the SE)!!! Occult 4 gives me an 88% chance. Bingo...... A very nice event. So bright in fact that I set aside my Astrid and took out the QHY174M-GPS which allowed me to capture the event at 50fps and a SNR of 8.6 (still bright at 50fps)!! Nowhere to be found on OW. Yes, I like OW.... but if you Just rely on it, you are probably missing some nice ones. George

Everyone, Now that the eclipse and NEAF are behind us, do we want to plan to have another virtual meeting? Any suggestions for a topic to concentrate on? Preferences for a date/time? Also, not sure what to do about Makhaon on 11 May at 21:31 local time. It is a pretty good event--especially with Kevin G and Rick nearly perfectly positioned. Fairly wide path covers Toronto, Buffalo, Rochester, Binghamton, and NYC--although the sunset would likely make it very tough for those in/near the first 3 cities. It is a high value Jupiter Trojan that has only had a single one-chord observation up until now. Combined mag is 12.4, drop is 3.9, duration 4.4 s, and reasonably high (mid-30's) in the west. Out here in the (relative) west it is dicey as the sun is only about 13 degrees below the horizon--also in the west, of course. With the timing after sunset, I'll be limited to a single chord try. I have a placeholder in OW right now, but I'll find a position on the southern side (less driving) roughly halfway between the edge of the shadow and next observer north unless there are other suggestions/requests. Steve