I have a "block" regarding how to set up an Obstructed Horizon. I want 45 degrees between 0 and 179 and 15 degrees between 180 and 359. I tried the following but nope - I tried Help but ...


0 45
179 45
180 15
359 15

Any help would be greatly appreciated. 

Thanks

I noticed tonight that when imputing the start time = 2021-10-16 UT-5, the output will be +5. The issue just began today as I noticed bad ephemerides for 2019 XS all of a sudden. Below is the output for 2021 TG14 as an example. It appears okay when simply generating an ephemeris for UT and not local time. I contacted Horizons concerning this weirdness.

Kenneth Drake

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Ephemeris / API_USER Sun Oct 17 19:24:04 2021 Pasadena, USA      / Horizons   
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Target body name: (2021 TG14)                    {source: JPL#3}
Center body name: Earth (399)                    {source: DE441}
Center-site name: (user defined site below)
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Start time      : A.D. 2021-Oct-16 00:00:00.0000 UT+05:00
Stop  time      : A.D. 2021-Oct-18 00:00:00.0000 UT+05:00
Step-size      : 60 minutes

Hi,

I have a problem when I want to create a new target with any designation.
On my chart I open object requestor and choose "enter coordonates" and put the RA and DEC coordonates on hours, for example RA 21 18 60 and DEC +40 36 35.
I "accept" it and clic on "more object information" and clic on create imaging project and I can see this :
-coordonates of my new object is : -03h49m10.99s -57°17'45" !
It is impossible to modify !

What is wrong on my action ?

Nicolas Outters

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The MP 2021 TX14 is predicted to reach ~16.6 magnitude on 2021 Oct 19 @0600 UT in Fornax. It may be observable in the southern hemisphere. The attached file contains the osculating elements from JPL's HORIZONS website from Oct 16 to Oct 26 at 6 hour intervals. Closest approach according to the CNEOS website is Oct 19 @1507 at Re 0.00343 AU. The elements appear to be based on a 9 day observation arc, so should be good. Here's the link to the JPL page for this MP:

Small-Body Database Lookup (nasa.gov)

Happy hunting,

Phil S.

I recently purchased SkyTools Visual 4 - great app. I have not used SkyTools in 5+ years - migrated to MAC. I used ST3 for 4+ years. As I recall there was an airmass filter I think. If yes, is there something like that in ST4? I guess I could simulate with an obstructed Horizon. Any feedback would be welcome. Thanks.

Another really close approach not discovered until a day after. Most likely due to the proximity of the Sun. A real screamer moving over 55'/min! Faint (14th) and incredibly close (49,097Km) at 22:16CDT Oct.10. Orbit uncertainty was 7 but there were 14 observations over a 3 day period (Oct 11-14) - ATLAS-HKO, Haleakala, Visnjan Observatory, Tican, and Kitt Peak. Where were we? Crazy stuff!

I'd like you guys to know that I am thinking about observing close approaches and how to make SkyTools do that better. Eventually I will improve the code, but until then I can offer some advice. You guys may already know this, but just in case...

Because the number of minor planets has grown so large, I have had to come up with some creative ways of speeding things up for both general use, and plotting on the charts (two very different problems to solve). As a result things got very complicated. I added pre-calculations at the time when the elements are added, so that they will calculate faster later, and separated minor planets into a special database just for plotting, which also unfortunately adds overhead when you add them to the database. In the years that I was developing ST4, I don't think I  spent more time on anything else. I had to go back to it again and again, trying things, and changing the database design, until it seemed to be the right mix. In the process it all got very complex, and that makes it more likely that sneaky little bugs are hiding from me. The fact that some of you "power users" have had trouble with corruption of your database sort of keeps me up at night, so please keep an eye out for any smoking guns when things go wrong. Right now, I don't know where to start looking for the problem.

One thing to always keep in mind: how long anything related to minor planets takes is always a function of the number of minor planets in the database. So to make things move as quickly as possible when you add new element sets, be sure to keep the number of minor planets to a minimum in the database. Presumably you guys aren't interested in faint outer solar system objects, so don't have them in your database. What I recommend is to use the Cleanup / Delete button on the Minor Planet Data dialog often. Remember, it won't delete any minor planets that are "in use:" in an observing list, log entry, have attachments, etc. So, you can even tell it to "Delete all minor planets" and that should be safe, as long as the ones you want to keep show up some place such as an observing list. Tip: some imports automatically create observing lists with all of the imported objects. By default these are found in the Auto Generated lists folder. These objects won't delete as long as they are in these lists, so by deleting these lists before you clean up the database, more minor planets will be deleted.

When adding minor planets I would limit them to NEOs only in order to keep things as nimble as possible. You can do that via the special MPC lists, or via the ASTORB download by checking only the NEO box.

Hey Phil, when doing an update in the asteroid files, in particular the NEA today or a DBPS, is there any particular places to have the date configured any certain way? Nightly Planner, etc?

I managed to record the trail of Nereid, one of the fainter satellites of Neptune at mag. 18.69, according to SkyTools 4 Imaging.

Nereid is the third largest of Neptune’s moons, and the second to have been discovered. It was discovered on 1st May, 1949 by the Dutch American astronomer Gerard P. Kuiper (for whom the Kuiper Belt is named) using photographic plates from the McDonald Observatory in Fort Davis, Texas. It is named after the numerous daughters, called Nereids, of the sea god Nereus in Greek mythology.

Nereid has a diameter of about 340 km (210 miles). It revolves around Neptune with a period of just over 360 days in a highly elliptical orbit—the most eccentric of any known moon—that is inclined by more than 7° to the planet’s equator. Its mean distance from Neptune is 5,513,400 km (3,425,900 miles), which is about 15 times farther from Neptune than Triton. Nereid is exceedingly faint, making observations with even the largest Earth-based telescopes very difficult.

I took 60x30 sec frames then after a Meridian flip, another 50x60 sec frames. I threw these into PixInsight which handled the Meridian Flip and differing exposure times without breaking a sweat.

Images taken with a Tak Mewlon 210 F11.5, Tak Reducer/Flattener x0.8 and ZWO ASI 294 MM Pro camera from our back garden in suburban Brisbane, under Bortle class 6 skies on 5th Oct 2021.

I have overlaid Screen Captures from SkyTools 4 Imaging to show some of the field stars as well as the lucky catch of the Minor Planet (1698) Christophe at mag. 16.63 (Diameter: 10 - 31 km). Perihelion Distance is 2.8 AU, Aphelion Distance is 3.5 AU. I haven't updated the Minor Planet database for a few months and wonder if this has led to the slight discrepancy?


When I set the capture time in ST4, the plotted position of Christophe did not match the actual trail in my series of images. In ST4 it seems that Christophe was “behind” the recorded position by 2 or 3 hours? ST4 is set for my back garden location in Brisbane and the Win 10 PC clock was synchronised with the Time Server.

Cheers

Dennis


   

   

   

Hi razvan,

This looks like one for you! Max brightness of 16.1 mag on the morning of Oct 10, but in daylight. I calculated the ephemeris for Siding Spring because I don't know where you're at in Australia. It's too far south for me & probably for BMD as well. This is a pretty good advanced warning. Usually they're right on top of us or past us like 2021 TV1 which also reached ~16 mag on Oct 3.

Today's DBPS search found 34 objects within 0.05 AU on Oct 9, another record. Perhaps the hunting is better now that the northern hemisphere has more dark time for the searches.

Good luck,

Phil S.