Date   

Re: another natural satellite of Earth... again.

Alan Harris
 

Paul Chodas has tentatively identified this with the Surveyor 2 Centaur rocket body, launched on September 20, 1966.  The very low Earth encounter velocity (0.6 km/sec is even low for lunar ejecta, so it is unlikely it is a natural body, even lunar ejecta, more likely space junk.

Alan

On 9/20/2020 2:30 PM, Sam Deen via groups.io wrote:
Hi all,

I'm surprised I didn't notice this any sooner, but a friend pointed out to me that the recently-discovered asteroid 2020 SO is on an orbit that, while not currently orbiting us, will be captured into Earth orbit for a few months later this year.

Current geocentric orbit:

Perigee 2020 Nov 3.251863 +/- 0.0224 TT = 6:02:41 (JD 2459156.751863)
Epoch 2020 Sep 18.0 TT = JDT 2459110.5 Find_Orb
q707812.420 +/- 2281 (J2000 equator)
H 28.3 G 0.15 Peri. 229.78793 +/- 0.10
Node 253.78959 +/- 0.0014
e 2.3556565 +/- 0.00905 Incl. 5.78461 +/- 0.0029
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

Due to perturbations by the Moon, it will dip below e=1 on October 15th:

Perigee 2020 Nov 18.985389 +/- 0.0761 TT = 23:38:57 (JD 2459172.485389)
Epoch 2020 Oct 15.0 TT = JDT 2459137.5 Find_Orb
M 359.13451846 +/- 0.052 (J2000 equator)
n 0.02473837 +/- 0.0016 Peri. 344.83330 +/- 0.030
a 0.16830513 +/- 0.00725 Node 210.49792 +/- 0.0031
e 0.9989798 +/- 3.96e-5 Incl. 49.43843 +/- 0.026
P 39.84 H 28.3 G 0.15 U 8.4
q 25685.3859 +/- 123 Q 0.33643856 +/- 0.0165
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

Then it will reach its first perigee on December 1, at which point the asteroid will peak at magnitude 14.0 (geocentric, it'll probably be higher from closer stations):

Perigee 2020 Dec 1.296073 +/- 0.182 TT = 7:06:20 (JD 2459184.796073)
Epoch 2020 Dec 1.3 TT = JDT 2459184.8 Find_Orb
M 0.01992107 +/- 1.3 (J2000 equator)
n 5.07228274 +/- 0.707 Peri. 176.20926 +/- 2.8
a724104.427 +/- 67503 Node 28.69067 +/- 0.45
e 0.9291863 +/- 0.000445 Incl. 34.04654 +/- 0.6
P 70.97d H 28.3 G 0.15 U 12.5
q 51276.5093 +/- 3999 Q 0.00933791 +/- 0.000683
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

Then it will reach its second perigee on 3 February 2021, slightly higher and a fair bit more uncertain (at this point it will peak at magnitude 15.2):

Perigee 2021 Feb 3.752433 +/- 4.02 TT = 18:03:30 (JD 2459249.252433)
Epoch 2021 Feb 3.75 TT = JDT 2459249.25 Find_Orb
M 359.99300257 +/- 21 (J2000 equator)
n 2.87651669 +/- 0.739 Peri. 162.35558 +/- 8
a 0.00706480 +/- 0.00119 Node 27.66278 +/- 3.4
e 0.7963238 +/- 0.00654 Incl. 29.51607 +/- 0.29
P 125.15d H 28.3 G 0.15 U 12.5
q 215261.182 +/- 20314 Q 0.01269067 +/- 0.0015
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

At this point, it will make another close approach to the Moon combined with just generally being ejected beyond Earth's hill radius, at which point its eccentricity will quickly increase and it will formally leave earth orbit (e=1) again in late May 2020, nominally May 21:

Perigee 2021 Mar 30.423267 +/- 49.1 TT = 10:09:30 (JD 2459303.923267)
Epoch 2021 May 21.0 TT = JDT 2459355.5 Find_Orb
q857161.590 +/- 556064 (J2000 equator)
H 28.3 G 0.15 Peri. 289.48583 +/- 70
Node 357.23445 +/- 20
e 1.0282245 +/- 0.209 Incl. 30.51023 +/- 16
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

Running back its close approaches to Earth (half out of curiosity, half to see if it's an old artsat) nothing particularly stands out. With its orbit up to present, it typically made close approaches to Earth every 18 years or so (so 2002, 1984, 1966, 1948, etc):

Perigee 2002 Apr 13.269629 +/- 27.3 TT = 6:28:15 (JD 2452377.769629)
Epoch 2002 Apr 13.28 TT = JDT 2452377.78 Find_Orb
q 0.05376521 +/- 0.00687 (J2000 equator)
H 28.3 G 0.15 Peri. 334.16949 +/- 0.55
Node 185.70790 +/- 12
e 20.1117748 +/- 1.4 Incl. 158.19267 +/- 0.29
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

Perigee 1984 Apr 6.864302 +/- 20.8 TT = 20:44:35 (JD 2445797.364302)
Epoch 1984 Apr 6.6 TT = JDT 2445797.1 Find_Orb
q 0.05414741 +/- 0.0158 (J2000 equator)
H 28.3 G 0.15 Peri. 337.88104 +/- 0.7
Node 186.47086 +/- 17
e 19.5215486 +/- 2.64 Incl. 157.57057 +/- 55
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

It did, however, briefly nominally orbit Earth briefly in the 1960s:

Perigee 1966 Nov 9.304185 +/- 12.4 TT = 7:18:01 (JD 2439438.804185)
Epoch 1966 Nov 9.3 TT = JDT 2439438.8 Find_Orb
M 359.98843786 +/- 2100 (J2000 equator)
n 2.76250351 +/- Peri. 224.06218 +/- 51
a 0.00725787 +/- Node 36.30149 +/- 80
e 0.7800141 +/- 17248 Incl. 32.49146 +/- 7
P 130.31d H 28.3 G 0.15 U 17.4
q 238852.490 +/- 2.74e+7 Q 0.01291912 +/- 0.188
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

Of course as you can see that approach is not very well constrained at all, but we can't rule it out. The only things to launch into heliocentric orbit during that time were (going backwards) Pioneer 6, Venera 3, Venera 2, Zond 3, and Luna 6, all in 1965, with nothing in 1966 or 1967. I think it's safe to say this object *most likely* isn't space debris. Furthermore thanks to its one-month observation arc it's possible to constrain its AMR to 0.023 +/- 0.035 m^2/kg- a very heavy spacecraft if not solid rock.

In summary: This 5-13 meter asteroid will be entering Earth orbit between October 15 this year and ~May 21 next year. It definitely hasn't been close relations with Earth since at least the mid 1960s, so is most likely natural.

~Sam



--
Alan Harris harrisaw@...
4603 Orange Knoll Ave. 818-790-8291
La Canada, CA 91011


Re: another natural satellite of Earth... again.

 

Dear Sam,

yes for this object at Sormano's Observatory we have computed
close encounters with Earth

http://www.brera.mi.astro.it/sormano/teca.html

and Moon

http://www.brera.mi.astro.it/sormano/tam.html

I computed a MOID of 0.013 AU (MPC give 0.016 AU) so this
data has not gave us a warning in a first time...strange...

Your elements are quite interesting, thank you

Cheers,
Francesco



--------------------------------------------------------
Francesco Manca

SORMANO ASTRONOMICAL OBSERVATORY (MPC code 587)
Localita' Colma del Piano
I-22030 Sormano (Co) - Italy
E-mail: obs.sormano@...
WWW: http://www.brera.mi.astro.it/sormano
--------------------------------------------------------


another natural satellite of Earth... again.

Sam Deen
 

Hi all,

I'm surprised I didn't notice this any sooner, but a friend pointed out to me that the recently-discovered asteroid 2020 SO is on an orbit that, while not currently orbiting us, will be captured into Earth orbit for a few months later this year.

Current geocentric orbit:

Perigee 2020 Nov 3.251863 +/- 0.0224 TT = 6:02:41 (JD 2459156.751863)
Epoch 2020 Sep 18.0 TT = JDT 2459110.5 Find_Orb
q707812.420 +/- 2281 (J2000 equator)
H 28.3 G 0.15 Peri. 229.78793 +/- 0.10
Node 253.78959 +/- 0.0014
e 2.3556565 +/- 0.00905 Incl. 5.78461 +/- 0.0029
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

Due to perturbations by the Moon, it will dip below e=1 on October 15th:

Perigee 2020 Nov 18.985389 +/- 0.0761 TT = 23:38:57 (JD 2459172.485389)
Epoch 2020 Oct 15.0 TT = JDT 2459137.5 Find_Orb
M 359.13451846 +/- 0.052 (J2000 equator)
n 0.02473837 +/- 0.0016 Peri. 344.83330 +/- 0.030
a 0.16830513 +/- 0.00725 Node 210.49792 +/- 0.0031
e 0.9989798 +/- 3.96e-5 Incl. 49.43843 +/- 0.026
P 39.84 H 28.3 G 0.15 U 8.4
q 25685.3859 +/- 123 Q 0.33643856 +/- 0.0165
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

Then it will reach its first perigee on December 1, at which point the asteroid will peak at magnitude 14.0 (geocentric, it'll probably be higher from closer stations):

Perigee 2020 Dec 1.296073 +/- 0.182 TT = 7:06:20 (JD 2459184.796073)
Epoch 2020 Dec 1.3 TT = JDT 2459184.8 Find_Orb
M 0.01992107 +/- 1.3 (J2000 equator)
n 5.07228274 +/- 0.707 Peri. 176.20926 +/- 2.8
a724104.427 +/- 67503 Node 28.69067 +/- 0.45
e 0.9291863 +/- 0.000445 Incl. 34.04654 +/- 0.6
P 70.97d H 28.3 G 0.15 U 12.5
q 51276.5093 +/- 3999 Q 0.00933791 +/- 0.000683
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

Then it will reach its second perigee on 3 February 2021, slightly higher and a fair bit more uncertain (at this point it will peak at magnitude 15.2):

Perigee 2021 Feb 3.752433 +/- 4.02 TT = 18:03:30 (JD 2459249.252433)
Epoch 2021 Feb 3.75 TT = JDT 2459249.25 Find_Orb
M 359.99300257 +/- 21 (J2000 equator)
n 2.87651669 +/- 0.739 Peri. 162.35558 +/- 8
a 0.00706480 +/- 0.00119 Node 27.66278 +/- 3.4
e 0.7963238 +/- 0.00654 Incl. 29.51607 +/- 0.29
P 125.15d H 28.3 G 0.15 U 12.5
q 215261.182 +/- 20314 Q 0.01269067 +/- 0.0015
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

At this point, it will make another close approach to the Moon combined with just generally being ejected beyond Earth's hill radius, at which point its eccentricity will quickly increase and it will formally leave earth orbit (e=1) again in late May 2020, nominally May 21:

Perigee 2021 Mar 30.423267 +/- 49.1 TT = 10:09:30 (JD 2459303.923267)
Epoch 2021 May 21.0 TT = JDT 2459355.5 Find_Orb
q857161.590 +/- 556064 (J2000 equator)
H 28.3 G 0.15 Peri. 289.48583 +/- 70
Node 357.23445 +/- 20
e 1.0282245 +/- 0.209 Incl. 30.51023 +/- 16
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

Running back its close approaches to Earth (half out of curiosity, half to see if it's an old artsat) nothing particularly stands out. With its orbit up to present, it typically made close approaches to Earth every 18 years or so (so 2002, 1984, 1966, 1948, etc):

Perigee 2002 Apr 13.269629 +/- 27.3 TT = 6:28:15 (JD 2452377.769629)
Epoch 2002 Apr 13.28 TT = JDT 2452377.78 Find_Orb
q 0.05376521 +/- 0.00687 (J2000 equator)
H 28.3 G 0.15 Peri. 334.16949 +/- 0.55
Node 185.70790 +/- 12
e 20.1117748 +/- 1.4 Incl. 158.19267 +/- 0.29
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

Perigee 1984 Apr 6.864302 +/- 20.8 TT = 20:44:35 (JD 2445797.364302)
Epoch 1984 Apr 6.6 TT = JDT 2445797.1 Find_Orb
q 0.05414741 +/- 0.0158 (J2000 equator)
H 28.3 G 0.15 Peri. 337.88104 +/- 0.7
Node 186.47086 +/- 17
e 19.5215486 +/- 2.64 Incl. 157.57057 +/- 55
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

It did, however, briefly nominally orbit Earth briefly in the 1960s:

Perigee 1966 Nov 9.304185 +/- 12.4 TT = 7:18:01 (JD 2439438.804185)
Epoch 1966 Nov 9.3 TT = JDT 2439438.8 Find_Orb
M 359.98843786 +/- 2100 (J2000 equator)
n 2.76250351 +/- Peri. 224.06218 +/- 51
a 0.00725787 +/- Node 36.30149 +/- 80
e 0.7800141 +/- 17248 Incl. 32.49146 +/- 7
P 130.31d H 28.3 G 0.15 U 17.4
q 238852.490 +/- 2.74e+7 Q 0.01291912 +/- 0.188
From 18 observations 2020 Aug. 19-Sept. 18; mean residual 0".16

Of course as you can see that approach is not very well constrained at all, but we can't rule it out. The only things to launch into heliocentric orbit during that time were (going backwards) Pioneer 6, Venera 3, Venera 2, Zond 3, and Luna 6, all in 1965, with nothing in 1966 or 1967. I think it's safe to say this object *most likely* isn't space debris. Furthermore thanks to its one-month observation arc it's possible to constrain its AMR to 0.023 +/- 0.035 m^2/kg- a very heavy spacecraft if not solid rock.

In summary: This 5-13 meter asteroid will be entering Earth orbit between October 15 this year and ~May 21 next year. It definitely hasn't been close relations with Earth since at least the mid 1960s, so is most likely natural.

~Sam


Re: 2020 SW = C378AD2 = close approacher

 

Dear Bill, All

thank you for your explanation.
Yes I agree that 2020 SW magnitude will be around 12 V and its
motion very fast more than 2700 arcsec/min on Sept. 24,
In my experience with very fast objects the guide on the motion
is hard and in this case depend on the fardware mount and conrol software
(also to the CCD download), at Sormano we have implemented a software to guide the mount
on the object's motion but in this case is needed to have an accurate
time and imaged the trail, in this case better to stop on the middle exposure in order to have
a good point for the measure.

Cheers,
Francesco

--------------------------------------------------------
Francesco Manca
 
SORMANO ASTRONOMICAL OBSERVATORY (MPC code 587)
Localita' Colma del Piano
I-22030 Sormano (Co) - Italy
E-mail: obs.sormano@...
--------------------------------------------------------
_._,_._,_


Re: 2020 SW = C378AD2 = close approacher

Bill J. Gray
 

Hi Francesco, all,

The incoming "speed from infinity" for this object
is about 5.7 to 6.1 km/s, well above the 2.5 km/s or
so area where you'd start to think about space junk or
lunar ejecta.

The perigee distance is now known to almost 1% (one
sigma), but the time is uncertain by over an hour. It
should reach about mag 12.7. I think once the perigee
circumstances are better determined, there may be some
interest in visually tracking this object in the amateur
community. (I think. I don't know much about visual
tracking of fast-moving asteroids. In the early hours
of 24 September, you'd see this as a mag 12.7 object
moving about half a degree a minute. You might even
be able to observe the light curve, I'd think.)

At present, it looks as if it should be relatively
easily seen from much of the Americas.

-- Bill

On 9/19/20 3:30 AM, Francesco Manca wrote:
Dear All.
just now I have computed for 2020 SW = C378AD2 discovered at G96 (see MPEC 2020-S83)
a very close encounter for this small object ( 4-10 meter)*
on 2020-09-24.45 *at the geocentric distance o*f  28000 km
*
see http://www.brera.mi.astro.it/sormano/teca.html*
*Could be another space debris?
Cheers,
Francesco


Re: 2020 SW = C378AD2 = SPACE DEBRIS?

 

..refined the computation as

date 2020-09-24.46    
Nominal 28094 km   
min 26299 km   
max 29769 km    

Francesco

--------------------------------------------------------
Francesco Manca
 
SORMANO ASTRONOMICAL OBSERVATORY (MPC code 587)
Localita' Colma del Piano
I-22030 Sormano (Co) - Italy
E-mail: obs.sormano@...
WWW: http://www.brera.mi.astro.it/sormano
--------------------------------------------------------


2020 SW = C378AD2 = SPACE DEBRIS?

 

Dear All.

just now I have computed for 2020 SW = C378AD2 discovered at G96 (see MPEC 2020-S83)
a very close encounter for this small object ( 4-10 meter)
on 2020-09-24.45   
at the geocentric distance of  28000 km

see http://www.brera.mi.astro.it/sormano/teca.html

Could be another space debris? 

Cheers,
Francesco


Re: meteoroid DT19E01 impacted Earth on 2019/03/04

Joe Masiero
 

Hi Sam,

That's really exciting that you were able to recover this object.  Congratulations, and great job on finding it.

As Dave mentioned, those data were followup of an object first observed by NEOWISE.  Sensitivity in the IR is effectively diameter-limited, as opposed to flux limited in visible-light surveys.  As such, it is highly unlikely that we detected something that was H~33, and doubly so that we detected it multiple times.  I believe the smallest object we discovered after the cryo mission was ~70 m, and the smallest object detected in a single frame image was ~8 m (during a streaked close-pass).  So this would strongly favor a more distant solution with a larger object.

Still, great job on the recovery, and thanks for looking for these kinds of things.  Hopefully this knocks it off the Sentry list.

Joe Masiero



On Thu, Sep 17, 2020 at 12:08 AM Sam Deen via groups.io <planetaryscience=yahoo.com@groups.io> wrote:
Hi Dave

thanks for your comments.

> This was the NEOWISE discovery N00eiw9 at the time. We hunted for
> it on two consecutive nights, March 4 and 5 UT.

Yup, that's exactly how I managed to find it myself actually. (side note: Also managed to recover N00eiw9 = 2019 DF2, will be submitting the astrometry soon enough)

> If you are very confident that it hit on Mar 4, then why bother to
> note that a recovery was attempted at "the expected location" on
> Mar 5? After all, your expected location was somewhere near the
> Aleutian Islands. My expected location was around 16.5 hr RA and
> +40 deg Dec.

I actually hadn't realized an impact was on the table until I found your observations and attempted to make a precovery. I did a few full steps in find_orb with an appropriate uncertainty and found what I posted here.

> I'll note that just because you can fit an orbit with an RMS of
> 0.01 arcsec doesn't mean it's the correct orbit. The observations
> themselves have uncertainties in the 0.06 to 0.11 arcsec range.
> I wouldn't be so confident of an impact. There are non-impacting
> orbits that fit the observations somewhere between our two extremes.

Indeed, that's about the uncertainty I saw in my measurements as well and partially why I assumed a set uncertainty of 0.05 arcseconds for the provided orbit. With a 0.11'' input uncertainty the range is not much higher:

Perigee 2019 Mar 4.695752 +/- 0.0729 TT = 16:41:52 (JD 2458547.195752)
Epoch 2019 Mar 4.5 TT = JDT 2458547.0 Find_Orb
q 1800.59920 +/- 1640 (J2000 equator)
H 35.7 G 0.15 Peri. 242.18342 +/- 37
Node 85.93484 +/- 60
e 3.8936309 +/- 3.13 Incl. 65.86300 +/- 18
From 5 observations 2019 Mar. 4 (8.5 min); mean residual 0".01
IMPACT at 4 Mar 2019 16:37:06.71 lat +20.25795 lon W154.75424

Although it seems find_orb doesn't strongly disfavor approaches with much higher distances (q=10,000 or 20,000 km or so) it very much doesn't like to simulate them because apparent (emphasis on apparent) systematics seem to appear in the residuals, exemplified by a q=10,000 km orbit:

Perigee 2019 Mar 4.893204 +/- 0.0498 TT; Constraint: q=10000km
Epoch 2019 Mar 4.5 TT = JDT 2458547.0 Find_Orb
q 10000.0053 +/- 0.0869 (J2000 equator)
H 32.8 G 0.15 Peri. 176.41570 +/- 10
Node 164.22183 +/- 8
e 15.4735772 +/- 11.6 Incl. 38.26277 +/- 1.5
From 5 observations 2019 Mar. 4 (8.5 min); mean residual 0".02

obs / RA resid / DEC resid
1. +0.025 -0.006
2. +0.003 -0.008
3. -0.042 +0.009
4. -0.020 +0.026
5. +0.033 -0.021

(the positive-negative-positive circling of the RA residuals certainly looks suspicious, but it seems find_orb finds it much more suspicious than I do.)


Also, to append to the message I originally sent: I made a slight mistake in putting the epoch to the day after the supposed impact, which causes all sorts of trouble for obvious reasons. Because of and due to this fact I had also disabled planetary perturbations in the initial orbit calculation. With an improved calculation as you can see above, the nominal orbit has the asteroid impacting just northeast of Hawaii (by pure coincidence, believe it or not, to being discovered and observed in Hawaii- considering that the earlier, simpler orbit showed it impacting nowhere near Hawaii).

At any rate, considering how close it would have theoretically impacted to the big island, even with a lot of perigee ranging, the upside to all of this is that it should be fairly easy to confirm or rule out if anyone on Hawaii had any fireball cameras with a clear view to the northeast/east on March 4... If it turns out not to be the case, apologies for the false alarm and my putting too much stock into find_orb's short-arc solutions once again.

~Sam
On Wednesday, September 16, 2020, 11:44:52 PM MST, David Tholen <tholen@...> wrote:


> While hunting for recoveries of the sentry asteroid 2019 DF2

This was the NEOWISE discovery N00eiw9 at the time.  We hunted for
it on two consecutive nights, March 4 and 5 UT.

> but assuming a generous error of 0.05'', we get this nominal
> geocentric orbit:
>
>    Perigee 2019 Mar 4.693908 +/- 0.0346 TT = 16:39:13 (JD 2458547.193908)
> Epoch 2019 Mar  5.0 TT = JDT 2458547.5                        Find_Orb
> q  1745.25329 +/- 758              (J2000 equator)
> H  35.8  G 0.15                    Peri.  213.44303 +/- 9
>                                    Node    83.44070 +/- 29
> e  3.9055305 +/- 1.25              Incl.  68.42507 +/- 8
> >From 5 observations 2019 Mar. 4 (8.5 min); mean residual 0".01
> IMPACT at  4 Mar 2019 16:34:30.62 lat +46.83317 lon W171.99243
>
> It seems to me that DT19E01 was very confidently a meteoroid about
> 10-40 cm across that impacted Earth around N46.82196 W172.00157
> (south of the Aleutian Islands) on late March 4, and it would seem
> nobody at all noticed- probably due to its very small size.

If you are very confident that it hit on Mar 4, then why bother to
note that a recovery was attempted at "the expected location" on
Mar 5?  After all, your expected location was somewhere near the
Aleutian Islands.  My expected location was around 16.5 hr RA and
+40 deg Dec.

> For anyone curious here was its heliocentric orbit prior to impact as well (Very highly inclined!):
>
>    Perihelion 2019 Jun 9.168206 +/- 6.84 TT =  4:02:13 (JD 2458643.668206)
> Epoch 2019 Mar  5.0 TT = JDT 2458547.5  Earth MOID: 0.0000  Ve: 0.0481
> M 250.40841802 +/- 14              (J2000 ecliptic)          Find_Orb
> n  1.13958226 +/- 0.0706          Peri.  308.40458 +/- 13
> a  0.90776254 +/- 0.0375          Node  343.54945 +/- 0.034
> e  0.1884055 +/- 0.012            Incl.  51.37001 +/- 3.1
> P  0.86/315.90d          H 35.8  G  0.15  U 11.0
> q 0.73673506 +/- 0.0426    Q 1.07879003 +/- 0.0349
> >From 5 observations 2019 Mar. 4 (8.5 min); mean residual 0".01

The orbit I have on file is even more inclined, but that's to be
expected when you assume a larger topocentric distance:

DT19E01
Epoch 2019 Mar  6.0 TT = JDT 2458548.5                  Tholen
M 334.98558              (2000.0)            P              Q
n  0.32621668    Peri.  101.23198    +0.19512505    +0.98075356
a  2.0899310      Node  180.40025    -0.43409446    +0.09273923
e  0.4952730      Incl.  87.08981    +0.87948179    -0.17181936
P  3.02          H  21.4          G  0.15
Residuals in seconds of arc
190304 T14  0.02+  0.01-  190304 T14  0.07-  0.03+  190304 T14  0.04+  0.03-
190304 T14  0.00  0.00  190304 T14  0.03-  0.04+                         

The fact that I didn't find it in the Mar 5 images indicates that
the topocentric distance wasn't as large as assumed.  The closer
one assumes the object was, the larger the ephemeris uncertainty,
and the hopes of recovery become that much smaller.

I'll note that just because you can fit an orbit with an RMS of
0.01 arcsec doesn't mean it's the correct orbit.  The observations
themselves have uncertainties in the 0.06 to 0.11 arcsec range.
I wouldn't be so confident of an impact.  There are non-impacting
orbits that fit the observations somewhere between our two extremes.






Re: Possible outburst of 11351 Leucus?

Michael S. P. Kelley
 

Hi all,

This appears to be a false alarm. A bright star about 2 arcmin away
has affected my automatic photometry, and I do not confirm the
outburst in a manual examination. It is unusual, in that it occurred
in 5 images over two days, but the object moves slowly. Thanks to
those who have offered to confirm!

Best,
msk

On Thu, Sep 17, 2020 at 2:36 PM Michael S. P. Kelley <msk@...> wrote:

Hi all,

In Zwicky Transient Facility data, 11351 Leucus appears to be ~2.0 mag
brighter than normal. We have good photometric coverage over the past
two months, showing it brightening as it approaches opposition, with a
nice lightcurve superimposed. However, the past five data points (1
from Sep 16, 4 from Sep 17 UTC) are much brighter than the previous
trend, ending Sep 15. No background objects at the asteroid's
position in PS1 images. If anyone can confirm and follow-up, please
do. Note, this is a Lucy mission target.

We are writing up an ATel with more details.

Cheers,
Mike Kelley


Re: Possible outburst of 11351 Leucus?

g_masi
 

Hi Mike,

I've just imaged it and I find it is at mag 18.4 R (unfiltered, R-mags for the reference stars from Gaia DR1). MPC gives it at 18.5 V.

Best

Gianluca Masi
470-Ceccano (Italy)

Il 17/09/2020 20:36, Michael S. P. Kelley ha scritto:
Hi all,
In Zwicky Transient Facility data, 11351 Leucus appears to be ~2.0 mag
brighter than normal. We have good photometric coverage over the past
two months, showing it brightening as it approaches opposition, with a
nice lightcurve superimposed. However, the past five data points (1
from Sep 16, 4 from Sep 17 UTC) are much brighter than the previous
trend, ending Sep 15. No background objects at the asteroid's
position in PS1 images. If anyone can confirm and follow-up, please
do. Note, this is a Lucy mission target.
We are writing up an ATel with more details.
Cheers,
Mike Kelley


Possible outburst of 11351 Leucus?

Michael S. P. Kelley
 

Hi all,

In Zwicky Transient Facility data, 11351 Leucus appears to be ~2.0 mag
brighter than normal. We have good photometric coverage over the past
two months, showing it brightening as it approaches opposition, with a
nice lightcurve superimposed. However, the past five data points (1
from Sep 16, 4 from Sep 17 UTC) are much brighter than the previous
trend, ending Sep 15. No background objects at the asteroid's
position in PS1 images. If anyone can confirm and follow-up, please
do. Note, this is a Lucy mission target.

We are writing up an ATel with more details.

Cheers,
Mike Kelley


Re: meteoroid DT19E01 impacted Earth on 2019/03/04

Sam Deen
 

Hi Dave

thanks for your comments.

> This was the NEOWISE discovery N00eiw9 at the time. We hunted for
> it on two consecutive nights, March 4 and 5 UT.

Yup, that's exactly how I managed to find it myself actually. (side note: Also managed to recover N00eiw9 = 2019 DF2, will be submitting the astrometry soon enough)

> If you are very confident that it hit on Mar 4, then why bother to
> note that a recovery was attempted at "the expected location" on
> Mar 5? After all, your expected location was somewhere near the
> Aleutian Islands. My expected location was around 16.5 hr RA and
> +40 deg Dec.

I actually hadn't realized an impact was on the table until I found your observations and attempted to make a precovery. I did a few full steps in find_orb with an appropriate uncertainty and found what I posted here.

> I'll note that just because you can fit an orbit with an RMS of
> 0.01 arcsec doesn't mean it's the correct orbit. The observations
> themselves have uncertainties in the 0.06 to 0.11 arcsec range.
> I wouldn't be so confident of an impact. There are non-impacting
> orbits that fit the observations somewhere between our two extremes.

Indeed, that's about the uncertainty I saw in my measurements as well and partially why I assumed a set uncertainty of 0.05 arcseconds for the provided orbit. With a 0.11'' input uncertainty the range is not much higher:

Perigee 2019 Mar 4.695752 +/- 0.0729 TT = 16:41:52 (JD 2458547.195752)
Epoch 2019 Mar 4.5 TT = JDT 2458547.0 Find_Orb
q 1800.59920 +/- 1640 (J2000 equator)
H 35.7 G 0.15 Peri. 242.18342 +/- 37
Node 85.93484 +/- 60
e 3.8936309 +/- 3.13 Incl. 65.86300 +/- 18
From 5 observations 2019 Mar. 4 (8.5 min); mean residual 0".01
IMPACT at 4 Mar 2019 16:37:06.71 lat +20.25795 lon W154.75424

Although it seems find_orb doesn't strongly disfavor approaches with much higher distances (q=10,000 or 20,000 km or so) it very much doesn't like to simulate them because apparent (emphasis on apparent) systematics seem to appear in the residuals, exemplified by a q=10,000 km orbit:

Perigee 2019 Mar 4.893204 +/- 0.0498 TT; Constraint: q=10000km
Epoch 2019 Mar 4.5 TT = JDT 2458547.0 Find_Orb
q 10000.0053 +/- 0.0869 (J2000 equator)
H 32.8 G 0.15 Peri. 176.41570 +/- 10
Node 164.22183 +/- 8
e 15.4735772 +/- 11.6 Incl. 38.26277 +/- 1.5
From 5 observations 2019 Mar. 4 (8.5 min); mean residual 0".02

obs / RA resid / DEC resid
1. +0.025 -0.006
2. +0.003 -0.008
3. -0.042 +0.009
4. -0.020 +0.026
5. +0.033 -0.021

(the positive-negative-positive circling of the RA residuals certainly looks suspicious, but it seems find_orb finds it much more suspicious than I do.)


Also, to append to the message I originally sent: I made a slight mistake in putting the epoch to the day after the supposed impact, which causes all sorts of trouble for obvious reasons. Because of and due to this fact I had also disabled planetary perturbations in the initial orbit calculation. With an improved calculation as you can see above, the nominal orbit has the asteroid impacting just northeast of Hawaii (by pure coincidence, believe it or not, to being discovered and observed in Hawaii- considering that the earlier, simpler orbit showed it impacting nowhere near Hawaii).

At any rate, considering how close it would have theoretically impacted to the big island, even with a lot of perigee ranging, the upside to all of this is that it should be fairly easy to confirm or rule out if anyone on Hawaii had any fireball cameras with a clear view to the northeast/east on March 4... If it turns out not to be the case, apologies for the false alarm and my putting too much stock into find_orb's short-arc solutions once again.

~Sam

On Wednesday, September 16, 2020, 11:44:52 PM MST, David Tholen <tholen@...> wrote:


> While hunting for recoveries of the sentry asteroid 2019 DF2

This was the NEOWISE discovery N00eiw9 at the time.  We hunted for
it on two consecutive nights, March 4 and 5 UT.

> but assuming a generous error of 0.05'', we get this nominal
> geocentric orbit:
>
>    Perigee 2019 Mar 4.693908 +/- 0.0346 TT = 16:39:13 (JD 2458547.193908)
> Epoch 2019 Mar  5.0 TT = JDT 2458547.5                        Find_Orb
> q  1745.25329 +/- 758              (J2000 equator)
> H  35.8  G 0.15                    Peri.  213.44303 +/- 9
>                                    Node    83.44070 +/- 29
> e  3.9055305 +/- 1.25              Incl.  68.42507 +/- 8
> >From 5 observations 2019 Mar. 4 (8.5 min); mean residual 0".01
> IMPACT at  4 Mar 2019 16:34:30.62 lat +46.83317 lon W171.99243
>
> It seems to me that DT19E01 was very confidently a meteoroid about
> 10-40 cm across that impacted Earth around N46.82196 W172.00157
> (south of the Aleutian Islands) on late March 4, and it would seem
> nobody at all noticed- probably due to its very small size.

If you are very confident that it hit on Mar 4, then why bother to
note that a recovery was attempted at "the expected location" on
Mar 5?  After all, your expected location was somewhere near the
Aleutian Islands.  My expected location was around 16.5 hr RA and
+40 deg Dec.

> For anyone curious here was its heliocentric orbit prior to impact as well (Very highly inclined!):
>
>    Perihelion 2019 Jun 9.168206 +/- 6.84 TT =  4:02:13 (JD 2458643.668206)
> Epoch 2019 Mar  5.0 TT = JDT 2458547.5  Earth MOID: 0.0000  Ve: 0.0481
> M 250.40841802 +/- 14              (J2000 ecliptic)          Find_Orb
> n  1.13958226 +/- 0.0706          Peri.  308.40458 +/- 13
> a  0.90776254 +/- 0.0375          Node  343.54945 +/- 0.034
> e  0.1884055 +/- 0.012            Incl.  51.37001 +/- 3.1
> P  0.86/315.90d          H 35.8  G  0.15  U 11.0
> q 0.73673506 +/- 0.0426    Q 1.07879003 +/- 0.0349
> >From 5 observations 2019 Mar. 4 (8.5 min); mean residual 0".01

The orbit I have on file is even more inclined, but that's to be
expected when you assume a larger topocentric distance:

DT19E01
Epoch 2019 Mar  6.0 TT = JDT 2458548.5                  Tholen
M 334.98558              (2000.0)            P              Q
n  0.32621668    Peri.  101.23198    +0.19512505    +0.98075356
a  2.0899310      Node  180.40025    -0.43409446    +0.09273923
e  0.4952730      Incl.  87.08981    +0.87948179    -0.17181936
P  3.02          H  21.4          G  0.15
Residuals in seconds of arc
190304 T14  0.02+  0.01-  190304 T14  0.07-  0.03+  190304 T14  0.04+  0.03-
190304 T14  0.00  0.00  190304 T14  0.03-  0.04+                         

The fact that I didn't find it in the Mar 5 images indicates that
the topocentric distance wasn't as large as assumed.  The closer
one assumes the object was, the larger the ephemeris uncertainty,
and the hopes of recovery become that much smaller.

I'll note that just because you can fit an orbit with an RMS of
0.01 arcsec doesn't mean it's the correct orbit.  The observations
themselves have uncertainties in the 0.06 to 0.11 arcsec range.
I wouldn't be so confident of an impact.  There are non-impacting
orbits that fit the observations somewhere between our two extremes.






Re: meteoroid DT19E01 impacted Earth on 2019/03/04

David Tholen
 

While hunting for recoveries of the sentry asteroid 2019 DF2
This was the NEOWISE discovery N00eiw9 at the time. We hunted for
it on two consecutive nights, March 4 and 5 UT.

but assuming a generous error of 0.05'', we get this nominal
geocentric orbit:

Perigee 2019 Mar 4.693908 +/- 0.0346 TT = 16:39:13 (JD 2458547.193908)
Epoch 2019 Mar 5.0 TT = JDT 2458547.5 Find_Orb
q 1745.25329 +/- 758 (J2000 equator)
H 35.8 G 0.15 Peri. 213.44303 +/- 9
Node 83.44070 +/- 29
e 3.9055305 +/- 1.25 Incl. 68.42507 +/- 8
From 5 observations 2019 Mar. 4 (8.5 min); mean residual 0".01
IMPACT at 4 Mar 2019 16:34:30.62 lat +46.83317 lon W171.99243

It seems to me that DT19E01 was very confidently a meteoroid about
10-40 cm across that impacted Earth around N46.82196 W172.00157
(south of the Aleutian Islands) on late March 4, and it would seem
nobody at all noticed- probably due to its very small size.
If you are very confident that it hit on Mar 4, then why bother to
note that a recovery was attempted at "the expected location" on
Mar 5? After all, your expected location was somewhere near the
Aleutian Islands. My expected location was around 16.5 hr RA and
+40 deg Dec.

For anyone curious here was its heliocentric orbit prior to impact as well (Very highly inclined!):

Perihelion 2019 Jun 9.168206 +/- 6.84 TT = 4:02:13 (JD 2458643.668206)
Epoch 2019 Mar 5.0 TT = JDT 2458547.5 Earth MOID: 0.0000 Ve: 0.0481
M 250.40841802 +/- 14 (J2000 ecliptic) Find_Orb
n 1.13958226 +/- 0.0706 Peri. 308.40458 +/- 13
a 0.90776254 +/- 0.0375 Node 343.54945 +/- 0.034
e 0.1884055 +/- 0.012 Incl. 51.37001 +/- 3.1
P 0.86/315.90d H 35.8 G 0.15 U 11.0
q 0.73673506 +/- 0.0426 Q 1.07879003 +/- 0.0349
From 5 observations 2019 Mar. 4 (8.5 min); mean residual 0".01
The orbit I have on file is even more inclined, but that's to be
expected when you assume a larger topocentric distance:

DT19E01
Epoch 2019 Mar 6.0 TT = JDT 2458548.5 Tholen
M 334.98558 (2000.0) P Q
n 0.32621668 Peri. 101.23198 +0.19512505 +0.98075356
a 2.0899310 Node 180.40025 -0.43409446 +0.09273923
e 0.4952730 Incl. 87.08981 +0.87948179 -0.17181936
P 3.02 H 21.4 G 0.15
Residuals in seconds of arc
190304 T14 0.02+ 0.01- 190304 T14 0.07- 0.03+ 190304 T14 0.04+ 0.03-
190304 T14 0.00 0.00 190304 T14 0.03- 0.04+

The fact that I didn't find it in the Mar 5 images indicates that
the topocentric distance wasn't as large as assumed. The closer
one assumes the object was, the larger the ephemeris uncertainty,
and the hopes of recovery become that much smaller.

I'll note that just because you can fit an orbit with an RMS of
0.01 arcsec doesn't mean it's the correct orbit. The observations
themselves have uncertainties in the 0.06 to 0.11 arcsec range.
I wouldn't be so confident of an impact. There are non-impacting
orbits that fit the observations somewhere between our two extremes.


meteoroid DT19E01 impacted Earth on 2019/03/04

Sam Deen
 

Hi all,

While hunting for recoveries of the sentry asteroid 2019 DF2 (images courtesy of Dave Tholen's NEO followup program), I happened across an unusually quick-moving object in the same area that I calculated a preliminary 8.5-minute arc for, the observations laid out below:

DECam10*sC2019 03 04.62366016 26 13.07 +38 11 46.9 23.0 r 568
DECam10 sC2019 03 04.62507116 26 13.46 +38 11 55.6 568
DECam10 sC2019 03 04.62648116 26 13.83 +38 12 04.1 568
DECam10 sC2019 03 04.62790616 26 14.24 +38 12 13.0 568
DECam10 sC2019 03 04.62957616 26 14.70 +38 12 23.1 568

While searching for further images I came across another series of images (also courtesy of Dave's program, thanks Dave!) from the following day at its expected location, with the target name "DT19E01" so curious, I searched up DT19E01 in the NEOCP removed objects list archive as well as in the ITF, and found it was reported to the NEOCP in March and never confirmed, with the ITF listing some much more robust observations that apparently Dave identified as well:

DT19E01 C2019 03 04.62368716 26 13.058+38 11 46.89 23.20GV T14
DT19E01 C2019 03 04.62509716 26 13.452+38 11 55.59 23.15GV T14
DT19E01 C2019 03 04.62650616 26 13.844+38 12 04.29 22.71GV T14
DT19E01 C2019 03 04.62793216 26 14.247+38 12 13.08 22.98GV T14
DT19E01 C2019 03 04.62960216 26 14.722+38 12 23.29 23.14GV T14

These produce a *much* cleaner orbit with a RMS of less than 0.02 arcseconds, but assuming a generous error of 0.05'', we get this nominal geocentric orbit:

Perigee 2019 Mar 4.693908 +/- 0.0346 TT = 16:39:13 (JD 2458547.193908)
Epoch 2019 Mar 5.0 TT = JDT 2458547.5 Find_Orb
q 1745.25329 +/- 758 (J2000 equator)
H 35.8 G 0.15 Peri. 213.44303 +/- 9
Node 83.44070 +/- 29
e 3.9055305 +/- 1.25 Incl. 68.42507 +/- 8
From 5 observations 2019 Mar. 4 (8.5 min); mean residual 0".01
IMPACT at 4 Mar 2019 16:34:30.62 lat +46.83317 lon W171.99243

It seems to me that DT19E01 was very confidently a meteoroid about 10-40 cm across that impacted Earth around N46.82196 W172.00157 (south of the Aleutian Islands) on late March 4, and it would seem nobody at all noticed- probably due to its very small size.

For anyone curious here was its heliocentric orbit prior to impact as well (Very highly inclined!):

Perihelion 2019 Jun 9.168206 +/- 6.84 TT = 4:02:13 (JD 2458643.668206)
Epoch 2019 Mar 5.0 TT = JDT 2458547.5 Earth MOID: 0.0000 Ve: 0.0481
M 250.40841802 +/- 14 (J2000 ecliptic) Find_Orb
n 1.13958226 +/- 0.0706 Peri. 308.40458 +/- 13
a 0.90776254 +/- 0.0375 Node 343.54945 +/- 0.034
e 0.1884055 +/- 0.012 Incl. 51.37001 +/- 3.1
P 0.86/315.90d H 35.8 G 0.15 U 11.0
q 0.73673506 +/- 0.0426 Q 1.07879003 +/- 0.0349
From 5 observations 2019 Mar. 4 (8.5 min); mean residual 0".01

~Sam


Re: ANN: Size, Mass and Density of Asteroids

Brad
 

Excellent! Quite a pain to go get this data from other sources, and you have made a very user friendly interface.

Brad Young PE
Visual:
Oberwerk 8 x 40 Mariner binoculars
Meade ETX-125 
22" f/4.2 UC Obsession
COSPAR 8336 =TULSA1 +36.139208,-95.983429 660ft, 201m
COSPAR 8335 =TULSA2 +35.8311  -96.1411 1083ft, 330m
Remote Imaging:
MPC I89 COSPAR 7777 38.165653 -2.326735 5150ft, 1650m Nerpio, Spain
MPC Q62 COSPAR 7778 -31.2733 149.0644 3400ft, 1122m Siding Spring, NSW, Australia 
MPC H06 COSPAR 7779 32.92 -105.528 7298ft, 2225m Mayhill, New Mexico USA 
MPC 323 COSPAR 7782 -32.008 116.135 984ft, 300m Perth, WA, Australia



On Wednesday, September 16, 2020, 5:19:17 AM CDT, Mike Kretlow <mike@...> wrote:


Hi to all !

I like to announce the first version of SiMDA (Size, Mass and Density of
Asteroids) - A Web Based Archive and Data Service.

Both the system as well as the first SiMDA data set,  is now available
to the community.

The SiMDA catalog (data set) is provided via Zenodo: DOI:

The SiMDA system itself : https://astro.kretlow.de/simda

I consider SiMDA in an early stage, nevertheless I think it is mature
enough to release it to the public. It is work in progress. More data
and features will be added in the future. Any suggestions, bug reports
(either concerning data or the system) and feedback in general is
welcome. About the status and issues (e.g. missing data etc.) please
refer to the website.

Background: Since longer I am interested in asteroid mass determination.
After some years of not working on that topic I became interested again
into that, triggered by the EPSC/DPS meeting in Geneva last year. But
before working again on own mass determinations I had the wish for an up
to date overview about asteroid densities in a modern and comprehensive
form (data set including all individual estimates), and also for a
survey of mutual asteroid-asteroid encounters, thus leading into two
projects. SiMDA is one of these, which I am presenting now.


Best regards,
Mike Kretlow







ANN: Size, Mass and Density of Asteroids

Mike Kretlow
 

Hi to all !

I like to announce the first version of SiMDA (Size, Mass and Density of Asteroids) - A Web Based Archive and Data Service.

Both the system as well as the first SiMDA data set,  is now available to the community.

The SiMDA catalog (data set) is provided via Zenodo: DOI: https://doi.org/10.5281/zenodo.4030319

The SiMDA system itself : https://astro.kretlow.de/simda

I consider SiMDA in an early stage, nevertheless I think it is mature enough to release it to the public. It is work in progress. More data and features will be added in the future. Any suggestions, bug reports (either concerning data or the system) and feedback in general is welcome. About the status and issues (e.g. missing data etc.) please refer to the website.

Background: Since longer I am interested in asteroid mass determination. After some years of not working on that topic I became interested again into that, triggered by the EPSC/DPS meeting in Geneva last year. But before working again on own mass determinations I had the wish for an up to date overview about asteroid densities in a modern and comprehensive form (data set including all individual estimates), and also for a survey of mutual asteroid-asteroid encounters, thus leading into two projects. SiMDA is one of these, which I am presenting now.


Best regards,
Mike Kretlow


HERA MISSION: a CubeSat dedicated by ASI to Prof Andrea Milani

 

I'm very happy that one of the two Cubesat developed for the HERA mission will be dedicated by ASI (Italian Space Agency) to Prof. Andrea Milani, well known of MPML community.  I'm proud to use his OrbFit program (from the first release in 1998) to calculate confidence region on asteroid close encounters, identifications and so on (I remember our intersting converstions in about small bugs and development) and also to give my contribute in the AZ&DEC, CCD pointing systems of the FLYEYE telescope where I hope in the future to be selected to partecipate inside the team of SSA NEOCC. Both HERA and FLYEYE were followed and simulated by him and staff at PISA Univ.

From ASI Web Site:
L’ASI in collaborazione con la comunità scientifica ha deciso di dedicare uno dei due CubeSat al professor Andrea Milani
A bordo di HERA viaggeranno anche due piccoli CubeSat che, una volta rilasciati nello spazio, potranno sorvolare da vicino la superficie dell’asteroide. Il secondo CubeSat è a guida italiana ed è stato intitolato ad Andrea Milani, professore di Meccanica Orbitale all’Università di Pisa nonché scienziato di fama internazionale e ideatore della missione dell’ESA Don Quijote, la cui eredità viene oggi raccolta da HERA.

https://www.asi.it/2020/09/lindustria-italiana-in-prima-linea-nella-missione-hera-dellesa/


Cheers,
Francesco

 
--------------------------------------------------------
Francesco Manca
 
SORMANO ASTRONOMICAL OBSERVATORY (MPC code 587)
Localita' Colma del Piano
I-22030 Sormano (Co) - Italy
E-mail: obs.sormano@...
WWW: http://www.brera.mi.astro.it/sormano
--------------------------------------------------------






Re: unusual found in the ITF

Andreas Doppler
 

Not new, it's 2016 JD, sorry for any confusion...

On 14.09.20 19:04, Andreas Doppler wrote:
Epoch 2020 May 31.0 TT = JDT 2459000.5                  Doppler
M 113.43780              (2000.0)            P               Q
n   0.99413052     Peri.  255.66623     -0.13659056     -0.98774411
a   0.9942764      Node   202.60452     +0.96767064     -0.11671804
e   0.3836571      Incl.   11.33242     +0.21202962     -0.10362658
P   0.99           H   20.8           G   0.15           U   7


unusual found in the ITF

Andreas Doppler
 

Epoch 2020 May 31.0 TT = JDT 2459000.5 Doppler
M 113.43780 (2000.0) P Q
n 0.99413052 Peri. 255.66623 -0.13659056 -0.98774411
a 0.9942764 Node 202.60452 +0.96767064 -0.11671804
e 0.3836571 Incl. 11.33242 +0.21202962 -0.10362658
P 0.99 H 20.8 G 0.15 U 7
Residuals in seconds of arc
K2051 F52 0.0 0.0 K205C T08 0.4+ 0.1- K205E T05 0.1+ 0.1-
K2051 F52 0.0 0.0 K205C T08 0.4+ 0.7+ K205F G96 0.1+ 0.1+
K2051 F52 0.0 0.1+ K205D 703 0.2+ 0.2- K205F G96 0.1+ 0.2+
K2051 F52 0.0 0.1+ K205D 703 1.1- 1.3- K205F G96 0.0 0.1-
K2055 F52 0.1- 0.1- K205D 703 0.5- 0.6- K205F G96 0.0 0.0
K2055 F52 0.0 0.1- K205D 703 0.4- 0.5+ K205L F51 0.0 0.0
K2055 F52 0.1+ 0.1- K205E T05 0.2- 0.5+ K205L F51 0.1- 0.0
K205C T08 0.3- 0.2+ K205E T05 0.6+ 0.8- K205L F51 0.1- 0.0
K205C T08 0.1- 0.5+ K205E T05 1.0+ 0.7+


{
"header" : {
"name" : "A.Doppler",
"email" : "@andreas_d",
"comment" : "unusual submitted 20200914"
},
"links" : {
"link_0" : {
"trksubs" : [
[
"P20ZVJo",
"20200501",
"F52"
],
[
"P20ZXoD",
"20200505",
"F52"
],
[
"A10mbox",
"20200512",
"T08"
],
[
"C170DK1",
"20200513",
"703"
],
[
"A10mg9V",
"20200514",
"T05"
],
[
"C2T0062",
"20200515",
"G96"
],
[
"P110Kxf",
"20200521",
"F51"
]
],
"orbit" : {
"arg_pericenter" : 255.66623,
"eccentricity" : 0.3836571,
"epoch" : 2459000.5,
"inclination" : 11.33242,
"lon_asc_node" : 202.60452,
"pericenter_distance" : 0.61281515,
"pericenter_time" : 2458886.392447
}
}
}
}


old object PLS2181

 

Peter Thomas from Australia has sent to me a msg
to suggest the identification of the old object
PLS2181 (obervations of the year 1960)  to be
linked with the multiopposition K07EH8J = PLS2181

I have computed the orbit, RMS of mag residuals =  0.32
and sent the linkage to MPC

Congratulation to Peter


Cheers,
Francesco

--------------------------------------------------------
Francesco Manca
 
SORMANO ASTRONOMICAL OBSERVATORY (MPC code 587)
Localita' Colma del Piano
I-22030 Sormano (Co) - Italy
E-mail: obs.sormano@...
WWW: http://www.brera.mi.astro.it/sormano
--------------------------------------------------------