Minor Planet (52768) 1998 OR2 Close approach

[bigmasterdrago]

Snagging a speeding rock from my backyard requires that I know where to look. Especially if the rock is near my visual limit is on any night through any scope. Conditions always vary. Generally these rocks are moving so fast (10s of seconds per minute) that spotting them usually becomes just a waiting game. 3 minutes of DEC usually is not an issue, but depending on where it is DEC wise, more than a little RA error spells disaster in finding the rock. As I use higher magnification to get deeper stellar magnitude reach, my FOV (error circle) gets smaller. I have great hope that the new v4Pro visual does a great job of giving me the location to look for these speedsters in my backyard. This will be so much fun {;=)

[PMSchu]

In that case it may be that any position predictions that you make 5 weeks in advance of the closest approach won't be sufficiently accurate. Then you'll need to get more current elements in a few weeks. I recall that for some events folks were updating the elements weeks & even days before the events in question.

If the MPCORB & ASTORB aren't being updated frequently enough, it will increase your error. It's predicted to be 10.9 mag at closest approach and moving 16.7"/min.

Hopefully you'll have good weather.

Phil S.

[bigmasterdrago]

Well, the weather has to be better than the last 6 weeks!! I had 4th magnitude skies a couple of nights ago so was unable to sweep up 2019 Y4 in 7x35 binos. Astorb is still showing last update on 2/27. So no new close approach rocks. JPL and MPCORB seem to be up to date. I've used Horizons (telnet) years ago but now their web interface is easy to use when access to the net is available. Horizons has always been the gold standard since they know the mass of all the solar system bodies to use in the computations. I sent you a private message

[PMSchu]

Kenneth,

You've probably already done this, but here's a simulation of the motion of 1998 OR2 on the night of 28 Apr 2020 as seen from ~20 miles SW of Columbus, OH. Note that the scope has a mirror diagonal finder on a Dobsonian mount.

[attachment=1259]

Almost like watching a satellite .

Phil S.

[bigmasterdrago]

When running the ephemeris for a NEO, is the RA & DEC topocentric or geocentric?

[theskyhound]

When running the ephemeris for a NEO, is the RA & DEC topocentric or geocentric?

They are J2000 Astrometric unless you select Display Apparent Coordinates in the Ephemeris menu. There are no geocentric coordinates in SkyTools because there is always a location specified. The only exception is when you set the location on the Ephemeris to Geocentric. For the exact definitions, see the topic about coordinate systems in the help.