Tuesday, June 25, 2019

Small Asteroid 2019 MO (NEOCP A10eoM1) impacted Earth on June 22

On 2019 June 22.40, the Atlas Project Survey (T08 Mpc code) found a small asteroid that was soon after put on the NEOCP list with the provisional designation A10eoM1 for the follow-up by other observers. The Minor Planet Center subsequently assigned the following official designation to this object 2019 MO (see update below).

Davide Farnocchia at JPL noticed "that the T08 NEOCP observations could generate an impact prediction matching the observed point and time on the earth of a fireball recorded on June 22 at about 21:30UT.  That led to an orbit - this is where A10eoM1 would have been,  based on the four ATLAS observations and assuming it really was this particular impactor - good enough to do precovery searches through the PanSTARRS data (F52 Mpc code)." (via Bill Gray, private communication).

In fact using all the available observations of 2019 MO NEOCP A10eoM1  by F52 & T08, FINDORB software finds an IMPACT on June 22, 2019 at 21:31:54UT at Lat +15.02 & Long W68.65 that seems remarkably close to data of a fireball off the South coast of Jamaica as shared on Twitter by Peter Brown & Frankie Lucena


Credit: FINDORB - B. Gray



Below you can see the event as captured by the GLM  (via F. Lucena)

Credit: SLIDER by RAMMB / CIRA @ CSU

According to P. Brown: Airwaves recorded by Bermuda infrasound station 2000 km North show periods which are consistent with 5 kT bolide corresponding to a 3m diameter object NEA impact.




This is only the fourth time in history that an impacting object is observed prior to atmospheric entry. The first time it happened was with asteroid 2008 TC3, the second was with asteroid 2014 AA, the third was 2018 LA that impacted Earth on 02 June 2018. Another space impacting object discovered prior to its to atmospheric entry was WT1190F but it is thought to have been a space debris, possibly  the translunar injection module of Lunar Prospector. For more info about 2008 TC3, 2014 AA and 2018 LA see also:




UPDATE - June 25, 2019 @15:40UT

M.P.E.C. 2019-M72  issued on 2019 June 25 at 14:59 UT assign the official designation 2019 MO to A10eoM1 with the following comment:

The orbit below indicates an impact with the earth's atmosphere around June 22 21:30 UTC.  This is in good agreement with the details determined by D. Farnocchia with the JPL Scout System (June 22 21:32 UTC +/- 15 minutes) and W. Gray (June 22 21:30:33 UTC +/- "a few minutes").                               

UPDATE - June 26, 2019 @06:40UT

The UHIfA (Institute for Astronomy - Univeristy of Hawaii) press release about 2019 MO is online on their website describing their effort to locate Pan-STARRS 2 (PS2) precovery images of the asteroid following Farnocchia's advice: "Luckily, the Pan-STARRS 2 (PS2) telescope on Haleakalā was operating at the same time, and two hours prior to the ATLAS observations had imaged the part of the sky where 2019 MO should have been seen. The asteroid was located on a part of the PS2 camera that is not fully operational, but PS2 scientists Robert Weryk and Mark Huber, at the University of Hawai'i Institute for Astronomy (IfA) and Marco Micheli at the European Space Agency (ESA), were able to analyze these PS2 images and find the asteroid."

A map of the predicted trajectory and final impact location for asteroid 2019 MO


Credit: Larry Denneau (IfA/ATLAS), Brooks Bays (SOEST)



by Ernesto Guido

Tuesday, May 14, 2019

New Comet C/2019 J1 (Lemmon)

CBET 4625 & MPEC 2019-J122, issued on 2019, May 12,  announce the discovery of a comet (magnitude ~17.5) in the course of the "Mt. Lemmon Survey" (G96), in images taken on 2019, May 04 with a 1.5-m reflector + 10K CCD. This object was reported as a comet by R. A. Kowalski and D. Rankin (G96, May 4). The new comet has been designated C/2019 J1 (Lemmon).  

I performed follow-up measurements of this object while it was still on the PCCP webpage. Stacking of 12 unfiltered exposures, 120 seconds each, obtained remotely on 2019, May 06.4 from H06 (iTelescope network) through a 0.25-m f/3.4 reflector + CCD, shows that this object is a comet with a diffuse coma about 10 arcsec in diameter.

My confirmation image (click on it for a bigger version)



M.P.E.C. 2019-J122, assigns the following preliminary orbital elements to comet  C/2019 J1: T 2019 Apr. 8.80; e= 0.97; Peri. =  167.59; q = 2.48;  Incl.= 24.54


Below you can see an image of comet C/2019 J1 (C0M96K2 was its PCCP provisional designation) taken on 2019, May 05, by its discoverers.

Credit: Catalina Sky Survey - Courtesy Kowalski & Rankin

by Ernesto Guido

Tuesday, April 30, 2019

Comets & Asteroids - Summary for March & April 2019

During the 2-month period March through April 2019, 6 new comets were discovered and there were 3 comet recoveries. "Current comet magnitudes" & "Daily updated asteroid flybys" pages are available at the top of this blog (or just click on the underline text here). See below for the "Other news" section.

The dates below refer to the date of issuance of CBET (Central Bureau Electronic Telegram)  which reported the official news & designations.

- Comet Discoveries

Mar 21 Discovery of C/2019 D1 (FLEWELLING)                  (CBET 4614)
Mar 21 Discovery of C/2019 E3 (ATLAS)                                (CBET 4615)
Apr 10 Discovery of P/2019 G1 = P/2011 O2 (PANSTARRS) (CBET 4618)* 
Apr 10 Discovery of C/2019 F1 (ATLAS-AFRICANO)           (CBET 4619) 
Apr 22 Discovery of C/2019 F2 (ATLAS)                                (CBET 4620) 
Apr 23 Discovery of P/2019 GG_21 (PANSTARRS)               (CBET 4621)** 

* G. V. Williams, Minor Planet Center, then identified additional pre-discovery (apparently stellar) observations obtained at Kitt Peak by T. H. Bressi with the 1.8-m Spacewatch II on 2009 Feb. 26 and at the XuYi Station of  Purple Mountain Observatory with a 1.04-m Schmidt telescope on 2009 Mar. 25.

**  Initially designated as minor planet 2019 GG21, there was one prior report of cometary activity in this object. R. Weryk and R. Wainscoat (F51, Apr. 4) reported a ~1".9 FWHM ("seemingly" larger than the 1".4 +/- 0".2 FWHM of nearby stars) and a slight asymmetry to the northwest.  No other credible cometary reports were received.  A  report received today of a "new comet" (remarking that 2019 GG21 was predicted to be "nearby") from S. Sheppard  (807,Apr. 4 and 5) noted that the object had a 21" tail in P.A. 310.  The object is therefore being redesignated P/2019 GG21.

- Comet Recoveries

Mar 10 Recovery of P/2003 L1 (SCOTTI) as P/2019 E1     (CBET 4612)
Mar 18 Recovery of P/2005 Y2 (McNAUGHT) as P/2019 E2   (CBET 4613)
Apr 03 Recovery of P/2006 F4 (SPACEWATCH) as P/2019 D2 (CBET 4616)

- Other news

Mar 06 Image sequence captured by CAM-H during the touchdown of @haya2e_jaxa @haya2_jaxa spacecraft with  asteroid (162173) Ryugu last month. Also on youtube http://bit.ly/2VFTpfy  #astronomy #asteroids #ryugu

Credits: JAXA

Mar 12 New paper on Arxiv by D. Seligman, G. Laughlin & K. Batygin: "Implications of the Small Spin Changes Measured for Large Jupiter-Family Comet Nuclei". Long-form blog post up on http://oklo.org/2019/03/12/on-oumuamua/

Mar 19 OSIRIS-REx caught asteroid Bennu ejecting particles from its surface. NavCam 1 imager captured the first-ever close-up observations of material being released from an “active asteroid.” 

Credits: NASA/Goddard/University of Arizona/Lockheed Martin

Mar 27 The gigantic 170 ft (52 m) boulder on asteroid Bennu #Bennu #OSIRISREx #Asteroid via Roman Tkachenko

Credits: NASA/Goddard/University of Arizona/Lockheed Martin

Mar 28 Active asteroid (6478) Gault imaged by Hubble Space Telescope. Images from Hubble show two narrow, comet-like tails of dusty debris streaming from the asteroid (6478) Gault. Each tail represents an episode in which the asteroid gently shed its material.

Credits: NASA, ESA, Meech & Kleyna (University of Hawaii) and Hainaut (ESO)

Apr 05 The Hayabusa2 deployable camera, DCAM3, successfully photographed the ejector from when the SCI  (Small Carry-on Impactor) collided with Ryugu’s surface"This is the world’s first collision experiment with an asteroid! In the future, we will examine the crater formed and how the ejector dispersed".  (see image below. Image credits: JAXA, Kobe University, Chiba Institute of Technology, The University of Occupational and Environmental Health, Kochi University, Aichi Toho University, The University of Aizu, and Tokyo University of Science)


UPDATE Apr 25 Crater formation where the Small Carry-on Impactor collided with Ryugu has been confirmed! These images compare the surface before and after the SCI collision.

Credit: Hayabusa2 JAXA


Apr 05 (CBET 4617) P. Jenniskens, SETI Institute and NASA Ames Research Center; and J. W. Baggaley, University of Canterbury, Christchurch, report that an outburst of delta Pavonid meteors (IAU shower 120; code DPA) has been detected by the CAMS New Zealand stations operated by P. Aldous (Geraldine) and I. Crumpton (West Melton).The parent comet is presumed to be C/1907 G1 (Grigg-Mellish), which was poorly observed in 1907, with parabolic orbital elements q = 0.924 AU, i = 110.06 deg, Peri. = 328.76 deg, and Node = 190.417 deg (equinox 2000.0) -- in good agreement when allowing for the motion of the node due to planetary perturbations.

Credits: NASA Meteor Shower Portal; CAMS SETI


Apr 15 New paper on Arxiv by D. Jewitt et al.: "Episodically Active Asteroid 6478 Gault".

Credit: Jewitt et al.


Apr 23 New paper on Arxiv by Chandler et al.: "Six Years of Sustained Activity from Active Asteroid (6478) Gault".

Credits: Chandler et al.


Apr 24 Three months of surface temperature maps of #67P nucleus from Rosetta suggest that only the upper layers are affected by temporal effects, keeping the immediate interior pristine.

Credits: F. Tosi et al - Nature Astronomy 2019


by Ernesto Guido

Sunday, March 31, 2019

Comets & Asteroids - Summary for Jan & Feb 2019

During the 2-month period January through February 2019, 14 new comets were discovered. Moreover inner main-belt minor planet (6478) GAULT developed a lengthening tail or trail. "Current comet magnitudes" & "Daily updated asteroid flybys" pages are available at the top of this blog (or just click on the underline text here). See below for the "Other news" section.

The dates below refer to the date of issuance of CBET (Central Bureau Electronic Telegram)  which reported the official news & designations.


- Comet Discoveries

Jan 02 Discovery of P/2018 Y2 (AFRICANO)      (CBET 4590)
Jan 07 Discovery of P/2019 A1 (PANSTARRS)   (CBET 4591)
Jan 08 Discovery of P/2019 A2 (ATLAS)            (CBET 4595)
Jan 10 Discovery of P/2019 A3 (PANSTARRS)   (CBET 4598)
Jan 17 Discovery of P/2019 A4 (PANSTARRS)   (CBET 4600)
Jan 17 Discovery of C/2019 A5 (PANSTARRS)   (CBET 4601)
Jan 17 Discovery of P/2019 A6 (LEMMON-PANSTARRS)   (CBET 4602)
Jan 23 Discovery of C/2019 B1 (AFRICANO)    (CBET 4604)
Jan 23 Discovery of P/2019 A7 (PANSTARRS)   (CBET 4605)
Feb 04 Discovery of P/2018 V5 (TRUJILLO-SHEPPARD)   (CBET 4607)*
Feb 04 Discovery of P/2019 A8 (PANSTARRS)   (CBET 4608)
Feb 04 Discovery of P/2019 B2 (GROELLER)    (CBET 4609)
Feb 07 Discovery of C/2019 A9 (PANSTARRS)   (CBET 4610)
Feb 27 Discovery of C/2019 B3 (PANSTARRS)   (CBET 4611)

* S. Sheppard reported that this object showed a ~9" tail in P.A. 276 on 2018 Nov. 7 and a 19" tail in P.A. 277 on 2019 Jan. 8.  The comet was detected by C. Trujillo on images taken by Sheppard.  R. Weryk reported prediscovery images that showed the object with a  1".3 FWHM (compared to 1".10 +/- 0".05 for nearby stars) on 2017 Oct. 28.


- Other news

Jan 07 CBET 4592, CBET 4593 (Jan 08), CBET 4596 (Jan 09), CBET 4599 (Jan 16) report that the following minor planets are binaries systems: (2337) BOUBIN, 2016 AZ_8, (7393) LUGINBUHL & (2070) HUMASON
 
Jan 08 CBET 4594 (issued on 2019, January 08) announces the serendipitous discovery by the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) team of unusual activity associated with the inner main-belt minor planet (6478) which appears to have developed a lengthening tail or trail. 





by Ernesto Guido

Thursday, February 28, 2019

Comets & Asteroids - Summary for Nov & Dec 2018

During the 2-month period November through December 2018, 10 new comets were discovered, cometary activity was detected for 1 previously discovered object (earlier designated as asteroids) and there was 1 comet recovery. Moreover an apparently asteroidal object with nearly-parabolic orbital elements was discovered. No cometary activity has yet been confirmed, but it has been given a cometary style A/ designation. "Current comet magnitudes" & "Daily updated asteroid flybys" pages are available at the top of this blog (or just click on the underline text here). See below for the "Other news" section.

The dates below refer to the date of issuance of CBET (Central Bureau Electronic Telegram)  which reported the official news & designations.

 - Comet Discoveries

Nov 08 Discovery of C/2018 V1 (MACHHOLZ-FUJIKAWA-IWAMOTO)     (CBET 4569 & 4572)
Nov 18 Discovery of P/2018 VN_2 (LEONARD)            (CBET 4573)*
Nov 20 Discovery of C/2018 U1 (LEMMON)                 (CBET 4574)
Dec 01 Discovery of C/2018 V2 (ATLAS)                       (CBET 4578)
Dec 01 Discovery of C/2018 V4 (AFRICANO)               (CBET 4579)
Dec 03 Discovery of C/2018 W1 (CATALINA)               (CBET 4580 & 4582)**
Dec 03 Discovery of C/2018 W2 (AFRICANO)              (CBET 4580)***
Dec 16 Discovery of C/2018 X2 (FITZSIMMONS)        (CBET 4583)
Dec 17 Discovery of C/2018 X3 (PANSTARRS)             (CBET 4584)
Dec 20 Discovery of C/2018 Y1 (IWAMOTO)                (CBET 4588)


* MPC inadvertently assigned it the minor-planet designation 2018 VN_2 by mistake.

** No cometary activity was detected at discovery, but it was given a cometary style A/ designation. On December 16, CBET 4582 reported that a faint coma had been detected in images taken with the CFHT at Mauna Kea on December 8.

*** Nearly simultaneous independent discoveries of a comet were reported on Nov. 27 via CCD images taken by H. Groeller (with the Catalina Sky Survey 0.68-m Schmidt telescope) and by B. M. Africano (with the Mount Lemmon 1.5-m reflector). G. V. Williams notes that Africano reported the object first, and that the object was posted on the Minor Planet Center's NEOCP webpage before Groeller's report arrived.  The Central Bureau received Africano's report at around Nov. 27.55 UT, or 21 minutes before Groeller's report was received.




- Cometary activity detected

Nov 29 Cometary activity detected in 2017 TW_13 =  P/2017 TW_13 (LEMMON)  (CBET 4576)

- Comet Recoveries

Dec 06  Recovery of P/2005 GF_8 (LONEOS) as C/2018 X1 (CBET 4581)

According to CBET 4579 (Dec. 01, 2018), an apparently asteroidal object designated A/2018 V3 with nearly-parabolic orbital elements (T = 2019 Sept. 8.66 TT, e = 0.990, q = 1.34 AU; at mag 21 and about 4 AU from the sun) was discovered. No cometary activity has yet been confirmed, but it has been given a cometary style A/ designation.

NEW NUMBERINGS OF SHORT-PERIOD COMETS (CBET 4589)

Further to CBET 4442, the following permanent numbers have been assigned to short-period comets based upon their being securely observed at multiple returns to perihelion.
                                                      
Designation/Name         Provisional Designations                Reference
363P/Lemmon               P/2011 VJ_5 = P/2017 W1               CBET 4455
364P/PANSTARRS        P/2013 CU_129 = P/2018 A2           CBET 4475
365P/PANSTARRS        P/2011 WG_113 = P/2017 U6          CBET 4490
366P/Spacewatch          P/2005 JN = P/2018 F2                    CBET 4497
367P/Catalina                P/2011 CR_42 = P/2018 H1             CBET 4510

368P/NEAT                   P/2005 R1 = P/2018 L3                      CBET 4526
369P/Hill                       P/2010 A1 = P/2018 P1                      CBET 4538
370P/NEAT                   P/2001 T3 = P/2018 P2                      CBET 4539
371P/LINEAR-Skiff         P/2001 R6 = P/2018 R1                      CBET 4552
372P/McNaught             P/2008 O2 = P/2018 P6                      CBET 4554

373P/Rinner                  P/2011 W2 = P/2018 R2                     CBET 4555
374P/Larson                  P/2007 V1 = P/2018 S1                      CBET 4558
375P/Hill                       P/2006 D1 = P/2018 T1                     CBET 4560


- Other news
 
Nov 08 CBET 4570, CBET 4575 (Nov 27), CBET 4586 (Nov 18) report that the following minor planets are binaries systems: (20882) 2000 VH57 & (6245) IKUFUMI & (250162) 2002 TY_57

Nov 20 On this day, 5 years ago: "Asteroids named after Thomas Pynchon & Stabia"  #astronomy #pynchon #stabia #asteroids


Dec 03 Dec 03 NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft completed its 2 billion-kilometer journey to arrive at the asteroid Bennu Monday. The spacecraft executed a maneuver that transitioned it from flying toward (101955) Bennu to operating around the asteroid. This series of images below, taken by the OSIRIS-REx spacecraft, shows Bennu in one full rotation from a distance of around 580 km. The spacecraft’s PolyCam camera obtained the 36 2.2-millisecond frames over a period of four hours and 18 minutes.

Credits: NASA/Goddard/University of Arizona

Dec 17 Comet 46P/Wirtanen imaged by E. Guido on 2018-12-17 at 11:45:26UT remotely from Bathurst Observatory Australia (MPC Q67). Single 20-second frame by 0.28-m f/2.2 reflector + CCD (ZWO 1600 Color) #astronomy #comets


Dec 18 Discovery by Sheppard, Tholen & Trujillo of new Solar System object 2018 VG18 ( nicknamed “Farout”) around 120 AU, making it the first Solar System object observed beyond 100 AU http://bit.ly/2S2thtI  & http://bit.ly/2S2thKe  #astronomy

Credits:  R. Molar Candanosa, S. Sheppard, Carnegie Institution for Science

Dec 20 Comet 46P/Wirtanen imaged on Dec. 13, 2018 by @NASAHubble space telescope https://go.nasa.gov/2QGAjIb  #astronomy #comets #Comet46pwirtanen #CometWirtanen

Credits: NASA, ESA, D. Bodewits and J.-Y. Li

Dec 21 Comet 46P/Wirtanen observed on Dec. 15, 2018 by astronomers at @AreciboRadar @NAICobservatory. The new radar observations provided the first definitive measurements of 46P/Wirtanen’s diameter, which is approximately 1.4 km (0.9 miles). http://bit.ly/2A9n48q  #astronomy #comets

Credits: Arecibo Observatory, NASA, NSF

Dec 26 Radar images of near-Earth asteroid 2003 SD220 obtained on Dec. 15-17 #astronomy #asteroids

Credits: NASA/Arecibo/USRA/UCF/GBO/NSF


by Ernesto Guido

Wednesday, January 16, 2019

ACTIVE ASTEROID (6478) GAULT

CBET 4594 (issued on 2019, January 08) announces the serendipitous discovery by the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) team of unusual activity associated with the inner main-belt minor planet (6478) which appears to have developed a lengthening tail or trail. 

"A median combination of seven 30-s exposures on 2019 Jan. 5 shows a tail or trail 135" long in p.a. 290 degrees. The tail/trail first appears in individual ATLAS exposures on 2018 Dec. 8, as identified by Denneau, with a median combined 120-s exposure showing a tail 30" long in p.a. 290 degrees.  There is no evidence of a tail in previous ATLAS imaging in January 2018."

Credit: ATLAS - discovery image

On January 08.7, I performed follow-up measurements of this object. Stacking of 10 unfiltered exposures, 120 seconds each, obtained remotely from Q62 (iTelescope network) through a 0.43-m f/6.8 astrograph + CCD, shows a tail about 2' and 30" long in PA 292.

My follow-up image (click on it for a bigger version)



Asteroid (6478) GAULT was discovered on 1988, May 12 by astronomers Carolyn & Eugene Shoemaker at the Palomar Observatory in California. It was named for American planetary geologist Donald Gault:

   Credit: Dictionary of Minor Planet Names - Schmadel

The active asteroids represent a newly recognized class of small body in the solar system: their peculiarity lies in having both the orbital characteristics of asteroids, residing in orbits interior to Jupiter’s and having the Tisserand parameter substantially larger than 3, and the physical properties of comets, in the form of comae or tails. 

Credit: D. Jewitt

The active asteroids have been referred to as ‘main-belt comets’ and ‘disrupted asteroids’ previously: the new designation is preferred both because some of the known cases are not located in the main belt and because the nature of the activity. Actually the causes of the activity are thought to be many and varied. As regards (6478) GAULT at this stage we can't rule out sublimation (or any other of the suggested mechanisms) in favor of an impact or viceversa. Hopefully more data will help sort out the cause of its activity. See the excellent David Jewitt's Active Asteroids webpage for more info about these fascinating objects and his paper "The Active asteroids" (The Astronomical Journal, 2012 March). 

Below you can see active asteroid (6478) GAULT imaged on 2019, January 11 at @INGLaPalma.


Credit: INGLaPalma



by Ernesto Guido

Thursday, December 20, 2018

New Comet C/2018 Y1 (Iwamoto)

CBET 4588 & MPEC 2018-Y52, issued on 2018, Dec. 20,  announce the discovery of a comet (magnitude ~12) by M. Iwamoto (MPC code 872) in images taken on 2018 Dec 18.8. The new comet has been designated C/2018 Y1 (Iwamoto).

I performed follow-up measurements of this object, while it was still on the PCCP webpage. Stacking of 5 unfiltered exposures, 20 seconds each, obtained remotely on 2018, December 20.5 from H06 (T20 - iTelescope network) through a 0.1-m f/5.0 astrograph + CCD, shows that this object is a comet with a diffuse coma about 1.5 arcmin in diameter and sharp central condensation.

My confirmation image (click on it for a bigger version)



MPEC 2018-Y52 assigns the following preliminary parabolic orbital elements to comet C/2018 Y1: T 2019 Jan. 27.16; e= 1.0; Peri. =  354.05; q = 1.14;  Incl.= 160.69

Below you can see a graph generated using the software Orbitas and showing the predicted magnitude (in red) versus the maximum height (for Northern Hemisphere). (click on the image for a bigger version). Preliminar orbit has the comet 0.2 AU from Earth with a peak magnitude of about 6 at the beginning of February 2019! (as always with comets, the future magnitudes reported here are only indicative).  Elongation at the beginning of February 2019 will be 160 degrees (maximum height will be very good for Northern Hemisphere at peak that is around 80 degrees, good for Southern until few days before peak then decreasing fast).




Congrats to Masayuki Iwamoto for his third comet discovery (the last one was just one month ago)! (see here for more info about his previous discoveries C/2018 V1 & C/2013 E2)

Below you can see the discovery image taken by M. Iwamoto at 05:11am of December 19, 2018 (Japanese Time) and the discoverer itself with his equipment.

Credit: M. Iwamoto


Masayuki Iwamoto - Credit: Hoshinavi


by Ernesto Guido