[meteorite-list] Detectability

From: Richard Kowalski <damoclid_at_meteoritecentral.com>
Date: Mon, 7 Sep 2009 15:50:28 -0700 (PDT)
Message-ID: <604207.77041.qm_at_web33906.mail.mud.yahoo.com>

We're due to start the 2009-2010 observing season tomorrow and I'm back on a night schedule so am a little sleepy and ready for a nap, but doing a quick check on an object the size you're looking for, assuming an albedo of 5%. I come up with 2007 DN41 as a candidate. I don't know the actual albedo, but you can do a more detailed search when you have the opportunity.

Running the ephemerides back from discovery, (17.9V) we could have discovered it as much as three weeks earlier under perfect conditions when it was about 12 million kilometers (7.5 million miles) away.

Your questions might be better answered if you posted on MPML. There are many more experts on the subject there who have already studied the problem in detail and can answer with more authority.

--
Richard Kowalski
http://fullmoonphotography.net
IMCA #1081
--- On Mon, 9/7/09, E.P. Grondine <epgrondine at yahoo.com> wrote:
> From: E.P. Grondine <epgrondine at yahoo.com>
> Subject: Re: Detectability
> To: "Richard Kowalski" <damoclid at yahoo.com>
> Cc: meteorite-list at meteoritecentral.com
> Date: Monday, September 7, 2009, 3:13 PM
> Richard - 
> 
> Thanks much again. Great work with TC3.
> 
> I am assuming that TC3 also had an orbit that created a
> detectable arc with your image analysis algorithm. Would a
> cometessimal directly inbound on a long period or short
> period orbit do so?
> 
> The problem is to take that 19.0V and turn it into a
> detection limit estimate for an inbound 30 meter
> carbonaceous chondrite, and further to turn that limit into
> an estimate of warning time. Sadly, those maths are well
> beyond me now.
> 
> Ed
> 
> 
> --- On Mon, 9/7/09, Richard Kowalski <damoclid at yahoo.com>
> wrote:
> 
> > From: Richard Kowalski <damoclid at yahoo.com>
> > Subject: Re: Detectability
> > To: "E.P. Grondine" <epgrondine at yahoo.com>
> > Cc: meteorite-list at meteoritecentral.com
> > Date: Monday, September 7, 2009, 5:03 PM
> > Ed,
> > 
> > checking my observing report from 6 October, 2008,
> the
> > night of discovery, the conditions were far from
> perfect and
> > the seeing wasn't that great. I reported it as 2.3
> > arcseconds full width half max for the night.
> > 
> > The night before was cloudy and I didn't head up to
> the
> > observatory. The night of impact the seeing was only
> > slightly better, but highly variable and both of
> these
> > nights were windy. Perfect nights have sub-arcsecond
> seeing
> > and our fwhm (1 arcsec pixels) is <1.8
> > 
> > With the 1.5-m we can reach 19.0V with good SNR using
> a
> > 5-second exposure AT Nautical Twilight.
> > 
> > --
> > Richard Kowalski
> > http://fullmoonphotography.net
> > IMCA #1081
> > 
> > 
> > --- On Mon, 9/7/09, E.P. Grondine <epgrondine at yahoo.com>
> > wrote:
> > 
> > > From: E.P. Grondine <epgrondine at yahoo.com>
> > > Subject: Detectability
> > > To: damoclid at yahoo.com
> > > Cc: meteorite-list at meteoritecentral.com
> > > Date: Monday, September 7, 2009, 2:44 PM
> > > Hi Richard - 
> > > 
> > > Thanks for the information, and congratulations
> on
> > TC3. 
> > > 
> > > I make that 320,000 miles something like 2 hours
> if it
> > had
> > > of been on a direct intercept orbit. I am
> assuming you
> > had
> > > nearly perfect sky conditions as well at your
> > observatory. 
> > > 
> > > I think this one is going to turn into photons in
> a
> > bucket
> > > and sky conditions. 
> > > 
> > > The items of interest are cometessimals, the
> smallest
> > > around 30 meters with 5 kilton impact force by
> my
> > current
> > > estimate, with 2 joined cometissimals around 60
> meters
> > and
> > > 15 megatons of impact force. (But I have been
> wrong
> > before,
> > > and reserve the right to be wrong in the
> future.)
> > > 
> > > No one in NASA seems to know what happened to
> the
> > CAPS
> > > analysis. It is probably sitting on a shelf
> somewhere
> > with
> > > the Apollo 11 Moon walk slowscan tapes.
> > > 
> > > E.P. Grondine
> > > Man and Impact in the Americas
> > > 
> > > 
> > >? ? ???
> > > 
> > 
> > 
> > 
> > 
> 
> 
> ? ? ? 
> 
      

Received on Mon 07 Sep 2009 06:50:28 PM PDT