CELESTIAL TARGETS: Bright Asteroids Await!!

Here is Your Chance to Monitor Some Fast-Moving Celestial Rocks
For those observers with telescopes 8-inch and larger, there are some magnificent minor planets (asteroids) that can be observed visually at this time, and tracking these rapid-moving celestial wanderers is an exciting nightly CCD or imaging program. There are several at this time that are very easy targets which can be seen moving against the background stars rapidly even in only a few minutes of elapsed time!

Note that the ones listed here are those which are NEO (Near Earth Object) or PHAS (Potentially Hazardous), or Unusual in classification by the Harvard MPC. Many of these swing by the earth in very elliptical orbits which make them difficult to view during much of their long orbits, but very favorable for short periods of time.

In addition, these selected have exhibited some fairly dramatic light variations that are easily recorded by modest equipment and even the eye, particularly in the case of 433 Eros.

NOTE that detailed daily ephemerides for these and all other asteroids visible are posted daily at the Harvard Minor Planet Center, and that there are elements available for uploading current information into popular PC programs such as Guide8, TheSky, Starry Night and others. Click on the "Bright Minor Planets" link under ASO TOOLS.

Also note that daily observations of both magnitude and precise position (astrometry) are posted by ASO under the Astrometry link on the ASO home page.

Below are the objects, their common names, or number designations, and the Harvard/MPC packed designations (in parentheses):

Object: 433 EROS (00433)- Magnitude 13.1
This is the famous Eros, which Arkansas Sky Observatory did extensive photometric study of in 1975 and was recognized as providing some of the first visual confirmation of light variations due to its potato shape. At this time Eros is in the constellation of ARIES, rising only minutes ahead of morning twilight, but will become more favorable as fall approaches.
Eros is moving slowly to the NORTHEAST nightly.

Object: 1685 TORO (01685) - Magnitude 13.9 (ASO July 15)
Here is one that is fun to watch speed by, now in the constellation of PEGASUS, rising high in the sky before dawn, about three hours ahead of Eros. At present, this big rock is more than 45 million kilometers away and moving rapidly through our skies northward and slightly eastward each night.

Object: 1373 CINCINNATI (01373) - Magnitude 16.1 (ASO July 15)
Although much dimmer than the previous two objects, 1373 is located very near 1685 Toro, in the constellation of ANDROMEDA. Latest measurements at ASO have this object moving very slowly northward nightly. It is bright enough to be detected visually in a good 12-inch telescope and easily imaged with an 8-inch and CCD.

Object: 21088 (21088) - Magnitude 15.4 (ASO July 15)
High in the constellation of PEGASUS in morning skies, this is one that is fun to watch and moving fairly rapidly against the distant stars. It is about at its brightest at this time and should be monitored nightly when possible. This one is moving pretty fast to the north and west by the hour.

Object: 4179 TOUTATIS (04179) - Magnitude 16.3 (ASO July 14)
This is one to watch, although it is presently in southern skies, just south of the Celestial Equator and in skies right before morning dawn. This object will keep you busy until October, since it will be brightening to magnitude 9 (!!) in September when it passes only [/i]four light days from Earth. This exciting NEO is moving slowly northward and slightly eastward each night, presently in the constellation of AQUARIUS.

Object: 2004 LJ1 (K04L01J) - Magnitude 15.7 (ASO July 14)
High in the skies at midnight in the constellation of CYGNUS, this is a very fast moving and exciting object, with some suspect light variations to it. It is moving west and north fairly rapidly as it flies by earth at this time.

Object: 2004 JR1 (K04J01R) - Magnitude 16.4 (ASO July 13)
Another high northern object, moving fast through our skies and presently in the constellation of VULPECULA. This is a fast-mover and difficult to image except with a very fast exposure, moving quite noticeably in only minutes as it zips to the east and south.
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Watch daily under the "Ephemerides" link on ASO for all minor planet postings from each previous night. There are some really exciting minor planets that are constantly in our skies and many new ones are found nightly....some which swing very close to the earth from time to time.

Best of luck chasing these celestial rocks!

Dr. Clay
ASO Petit Jean Mountain