Asteroid (1284) Latvia is a main belt asteroid about 37 km in diameter with an orbit around the Sun of 1572 Earth days. It was discovered by German astronomer Karl Reinmuth in July 1933. It was named after the Republic of Latvia. Reinmuth discovered a total of 395 asteroids, between the years of 1914-1956, and 2 comets, 30P/Reinmuth and 44P/Reinmuth. He named Asteroid (1111) Reinmuth for himself, a practice that is no longer permitted by the IAU. The video below shows about 1 hour of asteroid motion among the stars of Pegasus.
This is the third and last asteroid I imaged to capture data for the MPC. The purpose is to obtain an observatory code I can use when submitting astrometrical data for asteroids and comets to the Minor Planet Center. This data can be used to refine the orbits of these asteroids so it can be determined they pose no risk to the Earth. The primary interest is for data on the NEO’s (Near Earth Objects). These objects sometimes pass much closer to the earth than our own Moon. If one was to strike the Earth it would have devastating consequences for much of the Earth’s population. Main belt asteroids, like the three I have imaged pose much less of a threat, but should still be periodically measured. Collisions with other asteroids and gravitational perturbations with large mass objects can alter their orbits and increase the threat level. Studying asteroids long term can also provide data on their rotation period, albedo, mass and size. This is critical data for objects that might pass close to earth.
The requirements for providing data to the MPC, in order to obtain an observatory code, are strict and demanding. It is important for the data to be accurate, so it can be used reliably in scientific research. There are many requirements, or criteria to be met before a code is issued. I’m only going to go over the basics here, but if you want the detailed information, you can find it at the Minor Planet Center website: http://www.minorplanetcenter.net/iau/info/Astrometry.html
The basic process to obtain a code is to collect data for 3 asteroids over 2 different nights of measurements. You must make 3 measurements for each asteroid on each date. On each date the data should be collected with a separation of at least a half hour between measurements. Some asteroids move slowly and you want to detect the motion across the sky between measurements. So for the 3 asteroids, that’s nine measurements on each date. The positions of the asteroids must be calculated to an accuracy of 1 arc second. That’s why main belt asteroids are mainly used to collect the initial data. Their orbits a pretty well-known making it easier to check your reported positions against where the asteroid should be in its orbit.
For those not familiar with just how small 1 arc second error is, just think about the Earth as a whole. Looking from one horizon to the opposite horizon, encompasses 180 degrees. Each one of those degrees has 60 arc minutes. Each one of those arc minutes has 60 arc seconds. That’s 64,800 arc seconds horizon to horizon.
The easiest way to collect the data and measure accurate positions is by imaging the object, doing an astrometrical plate solve which measures the exact position of reference stars in the image matched against star catalogs like the UCAC4, and then measure the position of the object your checking, using that plate solution.
I use a program called Astrometrica, which was designed for this exact use. You load the images into the program after doing a calibration reduction on them (darks and Flats). The program will do the astrometrical plate solve and blink the images so you can find the object as it jumps from frame to frame while the stars hold their position. In theory this works beautifully. I’m still having some issues with the setup and parameters of the program to get consistently automated plate solving. Many times I’ll have to do a manual plate solve which involves overlaying the catalog positions of the stars over the stars on the images to match them up. This can be tedious. Another advantage of the software is it will put the data into the format required by the MPC. The data sets are sent by email and are read by computer, so they must be formatted correctly to be accepted by the database. I’ve already had to correct the formatting and resend the data.
Below is the data presented in the format required by the MPC. This (correctly formatted) data has already been sent to the MPC, and I am awaiting acceptance and the issuing of my observatory code. The issuance of the Observatory Code signifies my data has the required accuracy, and they can expect due diligence on my part, in regards to future data submitted.
TEL 127mm F7.5 APO Refractor + CCD
ACK MPCReport file updated 2015.09.16 14:04:22
[object] [date and time UT] [ R.A.] [Dec.] [Mag] [code]
00426 C2015 09 14.90177 23 14 51.95 +16 40 05.4 10.7 R XXX
00426 C2015 09 14.92634 23 14 50.57 +16 40 04.1 11.0 R XXX
00426 C2015 09 14.95090 23 14 49.13 +16 40 02.7 11.5 R XXX
00426 C2015 09 15.89872 23 13 41.41 +16 39 59.8 12.5 R XXX
00426 C2015 09 15.93424 23 13 39.43 +16 39 56.4 11.0 R XXX
00426 C2015 09 15.95882 23 13 38.11 +16 39 53.7 11.0 R XXX
01146 C2015 09 14.90890 23 33 46.81 +14 57 06.3 11.2 R XXX
01146 C2015 09 14.93347 23 33 45.10 +14 57 10.2 11.3 R XXX
01146 C2015 09 14.95802 23 33 44.34 +14 57 30.0 11.2 R XXX
01146 C2015 09 15.91679 23 33 14.76 +14 57 43.5 12.4 R XXX
01146 C2015 09 15.94138 23 33 13.71 +14 57 29.6 11.6 R XXX
01146 C2015 09 15.96596 23 33 12.59 +14 57 15.3 11.7 R XXX
01284 C2015 09 14.90420 00 10 20.60 +18 04 37.6 9.8 R XXX
01284 C2015 09 14.92876 00 10 19.33 +18 04 31.2 10.0 R XXX
01284 C2015 09 14.95333 00 10 18.02 +18 04 26.1 10.4 R XXX
01284 C2015 09 15.90228 00 07 27.20 +18 18 02.3 13.1 R XXX
01284 C2015 09 15.91324 00 07 26.62 +18 18 02.5 13.0 R XXX
01284 C2015 09 15.93782 00 07 25.26 +18 18 02.9 13.1 R XXX
—– end —–
The red headings were added to clarify each column. The xxx code is used until you are awarded your own three character observatory code.