Asteroid 2016 PR7 = 2008 MR4   HOME INDEX BACK NEXT
My first observation July 30, 2016
First magnitude 19.1
First constellation Capricornus
Oribtal period 4.00 years
Semi-major axis (AU) 2.52 AU
Orbit eccentricity 0.15
Orbit inclination 2.73 degrees
Absolute magnitude 17.5
Approximate size 0.5 - 1.2 miles
Next opposition December 2017

Latest data on 2016 PR7 from the IAU Minor Planet Center

The asteroid on the left is 2016 PR7, which I found in images taken on July 30, 2016. These pictures, taken a few days later, show this dim asteroid moving slowly to the west in Capricornus. It was about magnitude 19.6 at the time. This sequence shows its movement over a period of one hour.

I obtained other positions for this asteroid through August 24. Based on these positions, the IAU Minor Planet Center later determined that this asteroid is the same as 2008 MR4, which was imaged on two nights in 2008 by the Steward Observatory at Kitt Peak. It was apparently not observed again in the eight years separating these two sets of observations. The Pan-STAARS 1 telescope at Haleakala, Hawaii then observed this asteroid on two nignts ending on Septermber 30, 2016.


With all of these observations taken together, the arc length (period over which the asteroid has been observed) is 3014 days, which allows a fairly accurate orbit to be calculated. This is a main belt asteroid, orbiting the Sun between Mars and Jupiter over a period of about 4 years.

To the right is a brighter asteroid, designated 47619, which was about magnitude 18.2. Both of these objects are much too dim to be spotted visually through amateur telescopes.

Image details:  Each image is a 5-minute exposure, taken with an SBIG ST8300M imager and a Meade 14-inch LX850 telescope at f/6.


This chart shows the projected path of asteroid 2016 PR7 through Capricornus and Aquarius for the 120 days following my first observation.

(Chart created with TheSkyX software.)


This chart shows the orbit of 2016 PR7. The locations of the objects are for July 30, 2016, the date of my first observation.

(Chart created with JPL Small-Body Database Browser.)