It would be considered a "negative" or a miss as
you did "observe" the event, just did see an occultation or a
least not that you can pull out of the data.? I believe a "no
observation" is when you don't get a recording of the star during
the time of the event.
In the video, can you see the 2 stars as separate or kind of
separate?? Can you see the target star disappear or dim?? In
PyMovie, approximately what is the average for the counts for the
target star + 2nd star?
It is possible to manually modify the shape of target star mask to
reduce the contribution of the other star.? This may help.? No doubt
it depends on how close they are.? George Viscome just the other day
showed me how to do that.? Haven't tried it yet.? I recently had a
target star with a 2nd star of the same magnitude as the target so
close they looked like 1.? This analyzed OK, but I had very good
signal, about 20,000 counts I think.? You may need to see if and
experience person is willing to upload your file and check it out.?
Or Zoom/Skype and walk you through.
Yes, removing the reduce might have separated them enough if you can
already see them as separate. One of those things to test out.? You
could re-shoot the same target star and see.? Plate solving may have
more failures depending on the richness of the field, but at least
you have fine position control for tweaking in the target (just
don't forget to create a separate scope setup in your ASTRID).
Paul W
On 10/23/2024 5:35 PM, Garrett Tow
wrote:
toggle quoted message
Show quoted text
I redid the PyMovie analysis using the target as the tracker
and I got an uninterrupted signal (no tracking issues) all the
way through. I don't see any strong indication of a positive
occultation (it was unlikely to observe it to begin with), but
this may be due to noise/not separating the signal from the
neighboring star. I guess this one should be filed under "no
observation" rather than a miss.
?
Advice on how to best handle targets with neighboring stars
would be appreciated. I imagine I should remove all focal
reducers, but I figured I would double-check with y'all if that
is the recommended course of action.?
|
I redid the PyMovie analysis using the target as the tracker and I got an uninterrupted signal (no tracking issues) all the way through. I don't see any strong indication of a positive occultation (it was unlikely to observe it to begin with), but this may be due to noise/not separating the signal from the neighboring star. I guess this one should be filed under "no observation" rather than a miss.
?
Advice on how to best handle targets with neighboring stars would be appreciated. I imagine I should remove all focal reducers, but I figured I would double-check with y'all if that is the recommended course of action.?
|
I have an event I found that isn't found on a search with OWC.? I put it in its own occmnt file, and tried to upload it using the Upload Events tab.? It finds the file, but the Tags field is completely blacked out--no tags available.? When I try upload, it balks saying I have to add a tag.? Any idea what I have to do to make the Tags field work?
?
?
Steve
?
|
Re: (1717) Arlon 23-Oct Wednesday morning at 2 AM
Looks like I'm 34 km outside the shadow in travel distance--which I think means I should be well inside the 30 km projection of the orbital radius on the earth, right?? My only issues are it looks like it is right on the edge of the treeline for my observatory, plus we are expected to have some cirrus clouds that night with could combine with the moonlight to impact an observation from here.
?
Anyway, I'll list my site in OW, but there is a fair chance of it being a no-obs...
?
?
Steve C
?
From: Kevin <greenkevin01@...>
To: OccultNEUS <[email protected]>
Date: Monday, 21 October 2024 12:34 PM EDT
Subject: [OccultNEUS] (1717) Arlon 23-Oct Wednesday morning at 2 AM
Wednesday morning, 2:09 EDT, I'll be attempting to observe (1717) Arlon, an 8 km diameter rock, on the center line from West Hartford, CT. The asteroid is a claimed binary from the light curves. There have been 2 separate 1-chord observations of this asteroid so far, but so far no double dip has been reported into the system.
?
The Johnston webpage gives enough information to estimate that the binary separation is around 30 km, and the secondary is likely 4 km or so in size. Combined magnitude is 13.3 and max duration is 1.2 seconds.
?
?
The predicted shadow goes through Carbondale, PA and Akron, OH, then all the way to Santa Barbara, CA. Any observation 30 km from the center-line is scientifically useful.
?
I started writing this for NEUS, but maybe I should ping the NA IOTA group.
?
?
?
|
(1717) Arlon 23-Oct Wednesday morning at 2 AM
Wednesday morning, 2:09 EDT, I'll be attempting to observe (1717) Arlon, an 8 km diameter rock, on the center line from West Hartford, CT. The asteroid is a claimed binary from the light curves. There have been 2 separate 1-chord observations of this asteroid so far, but so far no double dip has been reported into the system.
?
The Johnston webpage gives enough information to estimate that the binary separation is around 30 km, and the secondary is likely 4 km or so in size. Combined magnitude is 13.3 and max duration is 1.2 seconds.
?
?
The predicted shadow goes through Carbondale, PA and Akron, OH, then all the way to Santa Barbara, CA. Any observation 30 km from the center-line is scientifically useful.
?
I started writing this for NEUS, but maybe I should ping the NA IOTA group.
?
?
?
|
@Steve I think you're right about loss of tracking. This explains the coordinated loss of signal between target and tracker even though the apertures are offset w.r.t. the direction of drift. The target star is the brightest one that remains in frame for the duration. I had picked another star besides the target for tracking, as I normally do, but perhaps it was not bright enough over all of the frames. You typically don't pick the target star to be the tracker star because of the loss of signal/drop in magnitude from the occultation that you would hopefully see, right? Perhaps in this scenario I could still use a dynamic mask on the target since I probably get a lumped signal including light from the nearby star pictured below. I was confused about how to retrieve the initial aperture positions after an analysis as they never reset correctly, but now I realize this is accomplished by using the "Back to 'mark'" button.
?
?
?
For target stars like the one above, should I be removing my focal reducers to have a longer focal length to help resolve the target star from its neighbor or is it better to look at the lumped signal using the focal reducers? The max duration of the event is predicted as 0.68 seconds, so maybe I could have removed the focal reducers and used 10 frames per second instead of using 30 fps with the focal reducers like I did?
?
?
?
@Paul I can generally see the target star across the duration without any sustained "blackout" periods. However, the brightness does change frame to frame with some frames clearly showing a nice bunch of white pixels while other nearby frames show the area as noise. At 30 fps on a 12 mag star under suburban skies and some moonlight, maybe this is to be expected? Yes, I didn't uncheck the "Show image contrast control" button before analysis. I now see that I have to uncheck this box to avoid the default rescaling. Thank you for the tip on positioning the no-star aperture. I will try to position it closer to the target at the same vertical level. Does it matter if the aperture boxes overlap? If the no-star aperture is fixed circular mask with default settings, then I assume that the boundaries of the aperture are not too significant. I don't have a brighter star for tracking compared to the target unless I try to split the star that neighbors the target, which I probably cannot do at this focal length (using f/6.3 + 0.5x reducers). The reason for the long duration video is that the error in the time reported on the OW Cloud event page is 1 minute and 27 seconds. On top of that error, ASTRID also includes some +/- cushion for catching satellites. I used the default recommendations by ASTRID's autorecord feature using the data imported from OW Cloud.
?
Best,
Garrett
|
Here's a silly question(s).? Visual what do you
see the stars doing?? Are that always visible?? Are they changing
brightness a lot?
I don't see any stars in your screen shot or did you forget to
uncheck the stretch before running the analysis (not that it matters for the analysis).? But without being able to see the stars the screen
shot doesn't tell us much.
If I assume the sections of the graphs that are not down at zero,
your signal is very low.? Do you have a brighter tracking star you
can use.? I am told it should be brighter than the target star if
possible.
FYI- your no star box should be closer to the target star and at
the same vertical level to better represent the background around
the target star, at least based on my training.
I'm curious, what is the reason for almost 4 minutes of video??
Hoping to catch satellite asteroids?
Paul W
On 10/20/2024 9:15 PM, Steve C via
groups.io wrote:
toggle quoted message
Show quoted text
Looks like you might be losing tracking as it drifts.?
Clouds/leaves I don't think would look like these--transitions
would be a more gradual rather than on/off like this.? Did you
try marking beginning and end of path for your tracking
aperture?
?
?
Steve C
?
From: Garrett
<garretttow1995@...>
To: OccultNEUS
<[email protected]>
Date: Sunday, 20 October 2024 7:36 PM
EDT
Subject: [OccultNEUS] Jumpy Light
Curves?
I'm still getting used to gathering and analyzing
data. For one of my attempted observations, I obtained a
light curve that would drop down to zero signal for both
my target aperture and tracker (reference star)
aperture. Is this what one sees from clouds or other
obstructions (nearby tree leaves)? It's difficult to
remember the exact conditions of an observation (nearby
obstacles/sky condition) when processing a couple days
after the fact. The relative locations of the apertures
are given in an image below (drift over the 228 second
recording due to rough polar alignment).
?
?
?
I don't understand the large peaks in the target
signal when the reference star signal stays flat at zero
around the frame ~5200 mark.
?
(490254) 2008 WC114 occults UCAC4 549-009676 on
2024-Oct-18 at 02:14 UT
()
?
Best,
Garrett
|
Looks like you might be losing tracking as it drifts.? Clouds/leaves I don't think would look like these--transitions would be a more gradual rather than on/off like this.? Did you try marking beginning and end of path for your tracking aperture?
?
?
Steve C
?
From: Garrett <garretttow1995@...>
To: OccultNEUS <[email protected]>
Date: Sunday, 20 October 2024 7:36 PM EDT
Subject: [OccultNEUS] Jumpy Light Curves?
I'm still getting used to gathering and analyzing data. For one of my attempted observations, I obtained a light curve that would drop down to zero signal for both my target aperture and tracker (reference star) aperture. Is this what one sees from clouds or other obstructions (nearby tree leaves)? It's difficult to remember the exact conditions of an observation (nearby obstacles/sky condition) when processing a couple days after the fact. The relative locations of the apertures are given in an image below (drift over the 228 second recording due to rough polar alignment).
?
?
?
I don't understand the large peaks in the target signal when the reference star signal stays flat at zero around the frame ~5200 mark.
?
(490254) 2008 WC114 occults UCAC4 549-009676 on 2024-Oct-18 at 02:14 UT (https://cloud.occultwatcher.net/event/1386-490254-63519-649235-U009676#)
?
Best,
Garrett
|
I'm still getting used to gathering and analyzing data. For one of my attempted observations, I obtained a light curve that would drop down to zero signal for both my target aperture and tracker (reference star) aperture. Is this what one sees from clouds or other obstructions (nearby tree leaves)? It's difficult to remember the exact conditions of an observation (nearby obstacles/sky condition) when processing a couple days after the fact. The relative locations of the apertures are given in an image below (drift over the 228 second recording due to rough polar alignment).
?
?
?
I don't understand the large peaks in the target signal when the reference star signal stays flat at zero around the frame ~5200 mark.
?
(490254) 2008 WC114 occults UCAC4 549-009676 on 2024-Oct-18 at 02:14 UT (https://cloud.occultwatcher.net/event/1386-490254-63519-649235-U009676#)
?
Best,
Garrett
|
By the way, since your scope has a motor drive,
have you tried going to the target with the drive on?? Or are you
using the pre-point to target an event in evening that occurs in
the morning so you can sleep??
I did my first such event last night. Successfully and it was a
positive to boot!
Paul
On 10/17/2024 9:55 PM, Paul Walker
wrote:
toggle quoted message
Show quoted text
I have yet to have my ASTRID crash.? Sometimes
the first wifi connection gets dropped when or right after
connecting with Real VNC.? But no crashes.? I have never let the
plate solve try for more that 20-30 seconds so have never have
let it fail.
Based on Steve being able to use 1 second exposures with his 5"
SCT's at 0.33x (and maybe 0.5x ? ) it makes sense that 0.5
seconds will work with your 8" SCT.? And probably less in a rich
star field.
Paul
On 10/17/2024 9:16 PM, Garrett Tow
wrote:
I tried pre-pointing out again last night and it seemed to
go really well (seemed because I haven't looked at the data
yet). I used a 0.5 second exposure. I got my pre-pointing
times down to about 20 minutes per target.
?
ASTRID crashed four times while I was pre-pointing on five
different targets through the night. Not too disruptive but
it's not a rare event. I could not find any pattern in what
triggers the error. Perhaps some log files get dumped or
ASTRID can be launched in a verbose mode to produce crash
logs?
?
Best,
Garrett
|
I have yet to have my ASTRID crash.? Sometimes
the first wifi connection gets dropped when or right after
connecting with Real VNC.? But no crashes.? I have never let the
plate solve try for more that 20-30 seconds so have never have let
it fail.
Based on Steve being able to use 1 second exposures with his 5"
SCT's at 0.33x (and maybe 0.5x ? ) it makes sense that 0.5 seconds
will work with your 8" SCT.? And probably less in a rich star
field.
Paul
On 10/17/2024 9:16 PM, Garrett Tow
wrote:
toggle quoted message
Show quoted text
I tried pre-pointing out again last night and it seemed to go
really well (seemed because I haven't looked at the data yet). I
used a 0.5 second exposure. I got my pre-pointing times down to
about 20 minutes per target.
?
ASTRID crashed four times while I was pre-pointing on five
different targets through the night. Not too disruptive but it's
not a rare event. I could not find any pattern in what triggers
the error. Perhaps some log files get dumped or ASTRID can be
launched in a verbose mode to produce crash logs?
?
Best,
Garrett
|
I tried pre-pointing out again last night and it seemed to go really well (seemed because I haven't looked at the data yet). I used a 0.5 second exposure. I got my pre-pointing times down to about 20 minutes per target.
?
ASTRID crashed four times while I was pre-pointing on five different targets through the night. Not too disruptive but it's not a rare event. I could not find any pattern in what triggers the error. Perhaps some log files get dumped or ASTRID can be launched in a verbose mode to produce crash logs?
?
Best,
Garrett
|
George: Thank you for the welcome. I will reach out if I have any questions. Please also do not hesitate to reach out to me if you would like to draw my attention to an occultation that is relatively accessible from Allentown, PA.
?
Paul: I appreciate the feedback. My collimation is currently fine and I don't believe the scope has ever been recollimated from factory settings. I purchased a "tri"-Bahtinov mask (not much price difference from a standard Bahtinov mask) which can be used to aid collimating efforts in addition to helping with focusing. I may pop off my corrector plate for a cleaning of the inside surface and may need to collimate (will mark off original positions to return to the original spot as close as possible). Here's a link that discusses the tri-Bahtinov mask a bit: ?
?
Steve: Brevity is not always a virtue! Thank you for taking the time to share all the details. Regarding the ASTRID crashes, I can get ASTRID to reliably crash when trying to use my manual mount specified as a "GoTo" mount in ASTRID when trying to plate solve during polar alignment. I was hopeful that I could use ASTRID to polar align, but from my experience it seems to really need the GoTo functionality to work and not just be emulated by rough manual adjustments. The polar align option is not present in ASTRID unless you configure your mount in ASTRID as a GoTo mount. So, I don't necessarily consider the crashing behavior I experienced as a bug since I was operating outside of the intended use. I have not contacted Mark about this. If you know how to use ASTRID's polar align feature for a non-GoTo mount, please let me know.
?
Best,
Garrett
?
|
Hey, no offense taken with the names--I've gotten Conrad my entire life and my family (for unknown reasons) will only call me Steven although I prefer Steve.
?
Here's what I've seen with my two Astrids for prepointing (your results may vary!):
?
- I have two near identical systems--Astrids semi-permanently mounted to C-5 SCTs.? One has the 0.33x Meade focal reducer, the other has the 0.5x reducer now provided with the Astrid.? I have somewhat (many?) more problems getting a prepoint solution with the 0.5x equipped system.? I do have another 0.33x reducer, but I use that on my observatory C-14 with a Watec 910 for events that are near home.? I need to trade off moving that reducer to the other C-5.
- I see two things driving why the 0.5x system fails more--the obvious is that FOV is smaller, and image quality (aberrations more so than diffraction/f# effects in my opinion) is also consistently worse.
- Both of these are on manual alt/az mounts with slow motion controls on each axis.? I know that they are all 3 degree per turn slow motions, so when the Astrid tells me move 2 degrees right, I know to turn the azimuth knob 2/3 turn clockwise, for example.? This really speeds things up.
- I try to level the mounts at least roughly, so azimuth is nearly purely azimuth and elevation is elevation--minimizing the coupling.
- I set the elevation before prepointing using an app on my cellphone, holding it gently against the C-5's tube--this really speeds things up.
- I don't use a magnetic compass, but just know in advance what bright star(s) I should be pointing near in azimuth.? Generally my move after the first successful prepoint is less than 10 degrees in azimuth and less than 2 degrees in elevation.? As you'd expect, with the alt/az mounts, prepoints near zenith are more painful than those closer to the horizon.
- I'm generally fussy with my focus prior to doing the first prepoint.
- I generally set my integration time to 1 second (both video and still) before starting, then reset the video rate to what I want for the occultation just before I start the auto-record (Mark recently added a reminder for this, which has already helped me avoid errors).? My focal lengths are short enough that trailing isn't an issue with this exposure time.? Gain is always on 16.
- I'm impatient, so if I feel the Astrid "over thinking" the first prepoint plate solve (aka--it takes more than 30 seconds or so), I cancel the prepoint, move somewhat in azimuth and retry.? I'd guess the first prepoint solve fails a third to half the time.
- I generally set the image stretch to 5:30 prior to prepointing (doesn't effect the Astrid's solutions).? I'm to the point now where I can see the image and often know when it will solve and when it will not.
- After the first successful prepoint, I can usually get on target (<10% of the field is what I shoot for) in about 3 to 6 more motions, and they seem to solve somewhat more reliably and faster.? This is 5 to 10 minutes of time.? If it is a weak field, you can wait a couple of minutes to see if the new prepoint field is better, or back off on the 10% goal.
- If I'm far off in one direction but not the other, I'll only adjust the large one on that prepoint cycle.
- One troubling thing I've had recently, is some fraction of the time when the prepoint plate solve fails, the Astrid software crashes, and I have to restart it (no power cycle, just restart the software).? This costs a minute or two as you have to load the event and set your exposure times again.? I need to report this to Mark--anyone else seeing this?
- Currently I leave myself 30 minutes to get each remote system on target once I arrive at the site.? That includes set-up, power up, prepoint, and final preps for recording.? This is more than enough most of the time, but on my most recent deployment my first station took closer to 45 minutes due to failed prepoints and an Astrid crash or two.? Note that that night had thin clouds, haze, and wind all factoring in.
?
Sorry--I have a hard time being brief!
?
?
Steve C
?
From: Paul <paulwaav@...>
To: OccultNEUS <[email protected]>
Date: Wednesday, 16 October 2024 10:29 AM EDT
Subject: Re: [OccultNEUS] Introduction
I don't have a good feel yet for what's a good exposure time for pre-pointing untracked scope and how much of a star trail is too much for the software.? Of course there is no one answer as it depends on effective focal length and aperture.? Not to mention how rich the star field is.? I've lost out on 2 events due to it taking too much time due to too many failed plate solves in sparse areas.? I expect there will be situations where one will not be able to pre-point.
Is there anyone out there that can give some guidance on how much star trailing is too much for plate solving to work??? Like maybe, if you can read readily see elongated stars the exposure is too long?
Yes, I would indeed advocate using you setting circles.? I always point in the general direction where using GoTo or a Dob (mind you I only have 8 events under my belt, 3 "positives") but for the last event using on of my Dobs I used a compass (compensating for magnetic/true north offset, its 15 degrees here in Vermont) and a digital level to get the altitude close.? It still took me ~20 minutes in a rich star field. But no doubt it reduced the number of plate solves required.? Part of the "problem" of course is not knowing for sure how far one moved the scope, especially with Dobs.? I plan to see about installing the digital setting circles that came with my 12.5" Dob, if for nothing else, to be able to see how much I move the scope. And of course give yourself much more time for the pre-point.
I use a Bahtinov mask to verify my focus, though with a little practice one can get it pretty much spot on just looking at the live video (depends some on the size of the screen you are using).? I don't know as the?Bahtinov mask will help in accessing the collimation.? Haven't heard of it being used for that.? Pointing at a moderately bright star and defocusing will show you if collimation is off.? But unless your collimation is way off I don't think it would be an issue for occultation timing.? Its not all that hard to collimate an SCT.? The only adjustment is on the secondary mirror, there should be a cap you pop off and you'll see 3 adjustment screws.? Point at a moderately bring star, without tracking you can use Polaris.? If you see an off center donut, the collimation is off.? I suppose I should first ask if you are familiar with collimating an SCT.
At least when I got Steve's name wrong it was his last name : )
Paul
On 10/15/2024 8:49 PM, Garrett Tow wrote:
Hi Paul,
?
Thank you for the welcome. My first attempt at using ASTRID was to try and use the telescope off of the wedge/tripod by placing the fork mount on the ground. I could not get good plate solves when trying this which led to a failure in attempting the pre-point approach. Perhaps I need to experiment more with the exposure duration. Too long of an exposure and the stars streak. Too short of an exposure and I was also not solving when the view happened to not have bright enough stars. I will try this again in the future. When roughly polar aligned, the plate solving was reliable and fast although it still takes me many iterations of manual adjustments to DEC/RA to get the target in view. I may try actually using the setting circle next time to speed things up.
?
I should also mention that I'm using a f/6.3 reducer and the IOTA 0.5x reducer that ships with ASTRID. I just purchased a tri-Bahtinov mask and hope this will lead to a higher quality focus and help identify any collimation issues.
?
I see in my previous email I typed "Steven" instead of "Steve" Conard. Apologies for that Steve!
?
Best,
Garrett
|
I don't have a good feel yet for what's a good
exposure time for pre-pointing untracked scope and how much of a
star trail is too much for the software.? Of course there is no
one answer as it depends on effective focal length and aperture.?
Not to mention how rich the star field is.? I've lost out on 2
events due to it taking too much time due to too many failed plate
solves in sparse areas.? I expect there will be situations where
one will not be able to pre-point.
Is there anyone out there that can give some guidance on how much
star trailing is too much for plate solving to work??? Like maybe,
if you can read readily see elongated stars the exposure is too
long?
Yes, I would indeed advocate using you setting circles.? I always
point in the general direction where using GoTo or a Dob (mind you
I only have 8 events under my belt, 3 "positives") but for the
last event using on of my Dobs I used a compass (compensating for
magnetic/true north offset, its 15 degrees here in Vermont) and a
digital level to get the altitude close.? It still took me ~20
minutes in a rich star field. But no doubt it reduced the number
of plate solves required.? Part of the "problem" of course is not
knowing for sure how far one moved the scope, especially with
Dobs.? I plan to see about installing the digital setting circles
that came with my 12.5" Dob, if for nothing else, to be able to
see how much I move the scope. And of course give yourself much
more time for the pre-point.
I use a Bahtinov mask to verify my focus, though with a
little practice one can get it pretty much spot on just looking at
the live video (depends some on the size of the screen you are
using).? I don't know as the?Bahtinov mask will help in accessing
the collimation.? Haven't heard of it being used for that.? Pointing
at a moderately bright star and defocusing will show you if
collimation is off.? But unless your collimation is way off I don't
think it would be an issue for occultation timing.? Its not all that
hard to collimate an SCT.? The only adjustment is on the secondary
mirror, there should be a cap you pop off and you'll see 3
adjustment screws.? Point at a moderately bring star, without
tracking you can use Polaris.? If you see an off center donut, the
collimation is off.? I suppose I should first ask if you are
familiar with collimating an SCT.
At least when I got Steve's name wrong it was his last name : )
Paul
On 10/15/2024 8:49 PM, Garrett Tow
wrote:
toggle quoted message
Show quoted text
Hi Paul,
?
Thank you for the welcome. My first attempt at using ASTRID
was to try and use the telescope off of the wedge/tripod by
placing the fork mount on the ground. I could not get good plate
solves when trying this which led to a failure in attempting the
pre-point approach. Perhaps I need to experiment more with the
exposure duration. Too long of an exposure and the stars streak.
Too short of an exposure and I was also not solving when the
view happened to not have bright enough stars. I will try this
again in the future. When roughly polar aligned, the plate
solving was reliable and fast although it still takes me many
iterations of manual adjustments to DEC/RA to get the target in
view. I may try actually using the setting circle next time to
speed things up.
?
I should also mention that I'm using a f/6.3 reducer and the
IOTA 0.5x reducer that ships with ASTRID. I just purchased a
tri-Bahtinov mask and hope this will lead to a higher quality
focus and help identify any collimation issues.
?
I see in my previous email I typed "Steven" instead of
"Steve" Conard. Apologies for that Steve!
?
Best,
Garrett
|
Garrett:
?
Welcome! Hope you can enjoy doing occultations. If we can help out in any way, just ask.
?
George
|
Re: Introduction/join the subject?
Greetings Paul and Garrett:
?
May I join your postings, and congrats for both of you using the ASTRID, I'm just a VTI user.
?
You may get plate solves faster by getting a better finder scope for your SCT Garrett. I still use (on both C-8 and 12.5" reflector) a 50mm finder with
16.8MM Mega Vista eyepiece, which reaches 10th magnitude here. Something like this should get you into the pre-point field much faster, you can make
finder charts tuned you your magnitude and that plate solve might go better, just my guess. Star hoping is much easier in a finder than the eyepiece.
Work at the desk making printed charts takes time, but reduces time in the field.?
?
Just a suggestion. I know GO-TO and plate solving, setting circles are to do away with chart work, but more detailed charts are worth adding to your toolkit.
Maybe I'm just too far behind the times and no plate solve is even needed, if you solve the field of view yourself.?
?
Best of luck, keep us posted!
Lawrence Garrett
Fairfax VT
?
?
?
?
?
|
Hi Paul,
?
Thank you for the welcome. My first attempt at using ASTRID was to try and use the telescope off of the wedge/tripod by placing the fork mount on the ground. I could not get good plate solves when trying this which led to a failure in attempting the pre-point approach. Perhaps I need to experiment more with the exposure duration. Too long of an exposure and the stars streak. Too short of an exposure and I was also not solving when the view happened to not have bright enough stars. I will try this again in the future. When roughly polar aligned, the plate solving was reliable and fast although it still takes me many iterations of manual adjustments to DEC/RA to get the target in view. I may try actually using the setting circle next time to speed things up.
?
I should also mention that I'm using a f/6.3 reducer and the IOTA 0.5x reducer that ships with ASTRID. I just purchased a tri-Bahtinov mask and hope this will lead to a higher quality focus and help identify any collimation issues.
?
I see in my previous email I typed "Steven" instead of "Steve" Conard. Apologies for that Steve!
?
Best,
Garrett
|
Hi Garrett,
Welcome.? I too am fairly new to this.? Got my ASTRID in
mid-August.? Since your mount is not a GoTo and the ASTRID does
plate solving, you will probably find that you don't that good of
a polar alignment.? Just leveling your
mount, setting your Dec to 90 degrees
and moving the mount to more or less center Polaris in your finder
scope should be good enough and save you time.
Paul
On 10/15/2024 4:44 PM, Garrett Tow
wrote:
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Hi Everyone,
?
I'm new to occultations and live a bit west of Allentown, PA.
I learned about occultations and found OccultNEUS through Steven
Conard.
?
My equipment is an Astrid and an 8" aperture Meade SCT on an
equatorial wedge (no go-to). I usually polar align via a drift
method using an illuminated reticle.
?
Best,
Garrett
|
Hi Everyone,
?
I'm new to occultations and live a bit west of Allentown, PA. I learned about occultations and found OccultNEUS through Steven Conard.
?
My equipment is an Astrid and an 8" aperture Meade SCT on an equatorial wedge (no go-to). I usually polar align via a drift method using an illuminated reticle.
?
Best,
Garrett
|
Steve C
George Viscome