Monday, August 2, 2021

New Comet C/2021 O3 (PANSTARRS)

CBET xxxx & MPEC 2021-P05, issued on 2021, August 01, announce the discovery of a new comet (magnitude ~20) on CCD images taken on July 26.5 UT with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala. The new comet has been designated C/2021 O3 (PANSTARRS)

Stacking of 15 unfiltered exposures, 240 seconds each, obtained remotely on 2021, July 30.3 from X02 (Telescope Live, Chile) through a 0.61-m f/6.5 astrograph + CCD, shows that this object is a comet with a compact coma about 8" arcsecond in diameter (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini, A. Valvasori).

Our confirmation image (click on the images for a bigger version; made with TYCHO software by D. Parrott)





MPEC 2021-P05, assigns the following preliminary orbital elements to comet C/2021 O3 (PANSTARRS): T 2022 Apr. 20.49; e= 1.0; Peri. =  299.88; q = 0.28 ;  Incl.= 56.72


Credit: MPC

This comet could become visible to the naked eye in 2022, reaching magnitude ~5. Below you can see a graph generated using the software Orbitas and showing the predicted magnitude (in red) versus its elongation from the Sun. Anyway, as always with comets, the future magnitudes reported here are only indicative. 


By Ernesto Guido

Saturday, July 24, 2021

New Comet C/2021 N3 (PANSTARRS)

CBET 5003 & MPEC 2021-O39, issued on 2021, July 22, announce the discovery of a new comet (magnitude ~20.5) on CCD images taken on July 13.5 UT with the Pan-STARRS1 1.8-m Ritchey-Chretien reflector at Haleakala (numerous pre-discovery observations going back an additional month were later identified). The new comet has been designated C/2021 N3 (PANSTARRS)

Stacking of 16 unfiltered exposures, 180 seconds each, obtained remotely on 2021, July 14.3 from X02 (Telescope Live, Chile) through a 0.61-m f/6.5 astrograph + CCD, shows that this object is a comet with a compact coma about 9" arcsecond in diameter elongated toward PA 230 (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini, A. Valvasori).

Our confirmation image (click on the images for a bigger version; made with TYCHO software by D. Parrott)



MPEC 2021-O39, assigns the following preliminary orbital elements to comet C/2021 N3 (PANSTARRS): T 2020 Aug. 13.96; e= 0.96; Peri. =  303.99; q = 5.69 ;  Incl.= 26.67


Credit: MPC


by Ernesto Guido

Friday, July 23, 2021

New Comet P/2021 N2 (Fuls)

CBET 5000 & MPEC 2021-N137, issued on 2021, July 15, announce the discovery of a new comet (magnitude ~18.3) on CCD images taken on July 09.4 UT with the Catalina Sky Survey's 0.68-m Schmidt reflector (pre-discovery Catalina observations from June 27 were identified later). The new comet has been designated  P/2021 N2 (Fuls)

Stacking of 28 unfiltered exposures, 60 seconds each, obtained remotely on 2021, July 10.1 from Z08 (Telescope Live, Oria) through a 0.7 m f/8 Ritchey Chretien + CCD, shows that this object is a comet with a compact coma about 8" arcsec in diameter and a tail 10" long in PA 250 (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini, A. Valvasori).

Our confirmation image (click on the images for a bigger version; made with TYCHO software by D. Parrott)


MPEC 2021-N137, assigns the following preliminary elliptical orbital elements to comet P/2021 N2 (Fuls): T 2021 Oct. 28.30; e= 0.47; Peri. =  174.65; q = 3.82 ;  Incl.= 12.99


Credit: MPC


by Ernesto Guido

Tuesday, June 29, 2021

Giant Oort Cloud Comet C/2014 UN271 (Bernardinelli-Bernstein)

On 2021 June 19, the circular MPEC 2021-M53 of Minor Planet Center announced the discovery of an asteroidal object by astronomers P. Bernardinelli & G. Bernstein (University of Pennsylvania) that they found in CCD exposures obtained with the 4.0-m reflector at Cerro Tololo Interamerican Observatory in the course of the "Dark Energy Survey", and which they reported as a previously unknown member of the Oort Cloud. The reported astrometry was spanning from 2014 Oct. 20 to 2018 Nov. 8. The new object was designated 2014 UN271. It was hidden among data collected by the 570-megapixel Dark Energy Camera (DECam) mounted on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory (CTIO) in Chile and was announced only now because, in the words of one of the discoverers, "finding TNOs with DES is a massive computational problem (my PhD was solving this problem). The search itself took 15~20 million CPU-hours, and the catalog production from our 80,000 exposures probably took more than that!"

According to the orbit calculated using data from 2014 to 2018, this object is likely to be a comet from the inner edge of the Oort Cloud. But 2014 UN271, despite its typically cometary orbit, appeared completely stellar in these archival images when it moved from 29 to 23 AU (for comparison, Pluto is 39 au from the Sun, on average). Below a simulation (made by T. Dunn) of the orbit of comet C/2014 UN271 showing it path in the Solar System from 1985 to 2049. 


A few days after the discovery announcement, 2014 UN271 has been found to show cometary appearance in new CCD images obtained by observers at station codes L81 & K93.Basically this object, that was first seen as an asteroid of magnitude ~22 by DES in 2014 at a distance of 29 AU, approaching the Sun was growing his coma and tails. As of June 2021, it was 20 AU from the Sun shining at a magnitude ~20.After the discovery of the cometary coma, the new comet has been designated C/2014 UN271 (Bernardinelli-Bernstein). This comet will reach perihelion, its closest point to the Sun, in January 2031 at about ~11 AU away from the Sun.

The absolute magnitude of C/2014 UN271 measured in DES images dated back to 2014-2018, has a value of H = 7.8 which suggests the body could be around 100–200 kilometers across. This value for the size of this comet is valid if we assume there was no contribution from a dust coma in that images. For scale the nucleus of comet 67P/Churyumov–Gerasimenko (that was the destination of the European Space Agency's Rosetta mission) is about 4km in diameter while nucleus of comet Hale–Bopp was about 60±20 kilometres in diameter. According to these data and with a reasonable degree of certainty, C/2014 UN271 it’s the biggest comet that we’ve ever seen!

Despite some exceptional features displayed by this comet, its considerable distance to perihelion should limit the peak magnitude to fairly modest values. Anyway, as always with comets, the future magnitudes reported here are only indicative. Below you can see a graph generated using the software Orbitas and showing the predicted magnitude (in red) versus its distance from the Sun.


We have been able to image this special comet on 2021 June 27 at 10UT from X02 (Telescope Live, Chile) with our CHI-1 telescope that is a 0.61-m f/6.5 astrograph + CCD. Stacking of 13 unfiltered exposures, 240 seconds each, clearly shows the coma developed by this object (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini, A. Valvasori). (click on the images below for a bigger version; made with TYCHO software by D. Parrott).

 

 

We had the pleasure of seeing our image featured in the article dedicated to this comet by the New York Times and written by science writer  R. G. Andrews.

Below an image from the Dark Energy Survey (DES) composed of some of the discovery exposures showing Comet Bernardinelli-Bernstein collected by the 570-megapixel Dark Energy Camera (DECam) mounted on the Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory (CTIO) in Chile. These images show the comet in October 2017, when it was 25 au away from the Sun. (Credit: Dark Energy Survey/DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA/P. Bernardinelli & G. Bernstein (UPenn)/DESI Legacy Imaging Surveys. Acknowledgments: T.A. Rector (University of Alaska Anchorage/NSF’s NOIRLab), M. Zamani (NSF’s NOIRLab) & J. Miller (NSF’s NOIRLab))

There is no doubt that this comet will be one of the most observed by astronomers for years to come.

by Ernesto Guido

Sunday, June 13, 2021

Bright Nova in Her - NOVA HERCULIS 2021

Following the posting on the Central Bureau's Transient Object Confirmation Page about a possible Nova in Her (TOCP Designation: TCP J18573095+1653396) we performed some follow-up of this object through a TEL 0.32-m f/8.0 reflector + CCD located in Nerpio, Spain and operated by iTelescope network (MPC Code I89).

On images taken on June 13.15, 2021 we can confirm the presence of an optical counterpart with R-filtered CCD magnitude +6.2 at coordinates:

R.A. = 18 57 30.98, Decl.= +16 53 39.6

(equinox 2000.0; Gaia DR2 catalogue reference stars for the astrometry).

This nova has been discovered by  Seiji Ueda, Kushiro, Hokkaido, Japan, at mag 8.4 on three 6-s exposures (limiting mag 13.0) taken with a Canon EOS 6D digital camera (+ 200-mm f/3.2 lens) on June 12.537 UT.

According to ATel #14704, a spectrum obtained by Munari et al. "has an overall blue shape and shows very pronounced broad absorptions (FWHM about 3000 km/s) compatible with P-Cyg components for Halpha, Hbeta and Hgamma blue-shifted by about 3100 km/s [...] Overall, the spectrum could be compatible with a nova of unusual large velocity". 

 

Our confirmation image (made with TYCHO software by D. Parrott):


 

An animation showing a comparison between our image and the archive POSS1 plate (1990-08-17):


 
A wide-field view with the nova at the centre:



UPDATE - June 16, 2021

According to CBET 4977, E. Kazarovets reports that the permanent GCVS designation V1674 Her has been given to this nova


by Ernesto Guido & Adriano Valvasori

Thursday, June 10, 2021

New Comet C/2021 K2 (MASTER)

CBET 4975 & MPEC 2021-L89, issued on 2021, June 09, announce the discovery of a new comet (magnitude ~19.0) on CCD images taken on May 23.0 UT with the "Mobile Astronomical System of the Telescope-Robots" (MASTER) auto-detection system (double 0.40-m f/2.5 reflector) at the South African Astronomical Observatory. The object was reported by MASTER as a new NEO candidate and has been found to show cometary activity by CCD astrometrists elsewhere. The new comet has been designated C/2021 K2 (MASTER)

Stacking of 35 unfiltered exposures, 120 seconds each, obtained remotely on 2021, June 02.4 from X02 (Telescope Live, Chile) through a 0.61-m f/6.5 astrograph + CCD, shows that this object is a comet with a compact coma about 15" arcsecond in diameter elongated toward PA 180 (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini, A. Valvasori).

Our confirmation images (click on the images for a bigger version; made with TYCHO software by D. Parrott)




MPEC 2021-L89  , assigns the following orbital elements to comet C/2021 K2 (MASTER): T 2021 Aug. 30.43; e= 0.98; Peri. =  342.26; q = 5.47 ;  Incl.= 100.67


by Ernesto Guido

Thursday, June 3, 2021

New Comet C/2021 J1 (Maury-Attard)

CBET 4972 & MPEC 2021-L11, issued on 2021, June 02, announce the discovery of a new comet (magnitude ~19.0) on CCD images taken by A. Maury and G. Attard on May 09.3 UT with the 0.28-m f/2.2 Rowe-Ackermann Schmidt astrograph at San Pedro de Atacama, Chile in the course of the  MAP (W94) survey.  The new comet has been designated C/2021 J1 (Maury-Attard). This is the first amateur comet discovery of 2021. It is also the first comet ever discovered using the synthetic tracking technique (using TYCHO software).

Stacking of 27 unfiltered exposures, 30 seconds each, obtained remotely on 2021, May 16.3 from X02 (Telescope Live, Chile) through a 0.61-m f/6.5 astrograph + CCD, shows that this object is a comet with a compact coma about 7" arcsecond in diameter (Observers E. Guido, M. Rocchetto, E. Bryssinck, M. Fulle, G. Milani, C. Nassef, G. Savini, A. Valvasori).

Our confirmation images (click on the images for a bigger version; made with TYCHO software by D. Parrott)



MPEC 2021-L11 , assigns the following orbital elements to comet C/2021 J1 (Maury-Attard): T 2021 Feb 19.45; e= 0.93; Peri. =  147.31; q = 1.74 ;  Incl.= 92.71

Click on the image below to see the discovery image

Credit: MAP survey


Credit: MPC



Congrats to Alain Maury, Georges Attard & Daniel Parrott!

by Ernesto Guido