Six little numbers that mean the whole world

Folks - the last few months have been stressful, full of nervous twitching and sweating - for Dave Grennan.

Roll your memory back to three and a bit years ago. Dave Grennan discovered his first asteroid - 2008 US3. The boards were alight with the news - but there was more to come. Dave discovered his second asteroid - 2009 FV19 a few months later bringing the tally from Ireland to 5.

But, the MPC are a finicky bunch... The rules for "discovery credit" were changed in the midst of these discoveries and there was a distinct possibility that all four asteroids discovered from these shores in 2008/2009 would be credited to others (multi million dollar facilities). The only thing a potential discoverer can do is wait, wait a bit more, wait a bit more... until the asteroid is "numbered" by the MPC - at which point, the discoverer is confirmed.

In the case of Dave's first discovery (2008 US3) numbering, by MPC standards, happened fairly quickly. Dave then named the asteroid after his Mum, Catherine.

In recent months, two of my own discoveries were numbered - we were up to three confirmed Irish discoveries (four if you include (9) Metis). So now Dave was going through that squeeky-bum time all on his own...

Tonight, Dave's second discovery (2009 FV19) - and Ireland's fifth - was finally numbered with full discovery credit to Dave. Here is the MPC numbering:

(312546) 2009 FV19
Discovery date : 2009 03 22
Discovery site : Raheny
Discoverer(s) : Grennan, D.

This is the culmination of a lot of hard work and patient waiting. But we now know for sure that Ireland has five confirmed asteroid discoveries:

Apr 1848 (9) Metis - Andrew Graham, Markree
Oct 2008 (309914) - Dave McDonald, Celbridge
Oct 2008 (215016) Catherinegriffin - Dave Grennan, Raheny
Mar 2009 (281507)- Dave McDonald, Celbridge
Mar 2009 (312546) - Dave Grennan, Raheny

So, Dave, the waiting is finally over and you can stop worrying. Congratulations on completing the "full-house" - and I know that those six little numbers mean the whole world to you - or should that be minor planet?

Dave

Congratulations Dave, I am happy for you that it worked out and that the credit stuck to you and your discovery.



Seanie.

Good news Dave G.

Question - what would be the circumstances that could have led to the accreditation to others of these discoveries? We have insufficient observational confirmation and measurements such that we can no longer be certain that a now confirmed and numbered asteroid is really the same as originally reported?

Mark C.

mjc wrote: Question - what would be the circumstances that could have led to the accreditation to others of these discoveries?
Mark C.

Hi Mark. Well its quite a long story so first I should refer you to this , which is the announcement of these new rules.

The important sentence here is;
"The discovery observation will be that observation which is the earliest-reported observations at the opposition with the earliest-reported second-night observation." Confused? Join the club! Why this is important needs a little explanation. Basically when you submit a two night discovery, what you are doing is linking your observations together and saying that the object you are reporting over two nights are the same object and do not refer to a known object. If the MPC agree, they issue a designation, what happens then is the MPC trawl through their list of unidentified observations (i.e one night observations, which were, a:) containing insufficient data to create even a preliminary orbit, b:) were not reported as a discovery at that time). If the person submitting two nights had not done so, these observations would remain lost forever and never be identified with a real object. So the MPC (now with a reasonable orbit) search these observations and now will always find earlier reported observations and link them to your new object. Also armchair hunters may well then take your orbit and trawl through the neat archives and find your object on plates which were never even spotted before.

Up till now it was simple, the person with the first two nights was the discoverer. This seems fair because that was the person who said, this is a new minor planet and I can prove it by a second night. Post the editorial notice given above, if at a later stage a single observation at the same opposition gets linked with your object that observation is designated the discovery observation. On one level you might think this is reasonable, however consider that without your two night linkage, the earlier observation would have remained lost in the nether regions of the MPC and never be linked with a known object. i.e. without your input, this object would not have been discovered. If you at the most recent MPC circular and look at the recent numberings, you will see an asterisk beside every single object discovered in 2011. This means that the discovery circumstances have been 're-assigned' according to the new rules. All of these are re-assigned to the large scale surveys beause these surveys scan almost the entire sky everymonth and the chances that there is a lost one nighter in the MPCs database for every single minor planet (even the undiscovered ones) are almost 100%.

So given all of the above, how did myself and dave retain our discoveries, the last line of the editorial states;
"Objects that have multiple-opposition orbits as of now will be grandfathered into the old scheme of assigning discovery credit."

Sorry for the long winded answer, but I know Mark likes detail:)

Your reply is really appreciated - though I I do have to think about the response.

Regardless of whether I understand these rules - well done in the final assignment.
Also, I'm sure there's more than just I that appreciate your response to my query.

Mark C.

Good to see them all numbered now and that you didn't get "robbed" of your asteroid discovery by the new rules.