Monday, March 1, 2021

New Comet C/2021 C4 (ATLAS)

CBET 4937 & MPEC 2021-D113, issued on 2021, February 26, announce the discovery of an apparently asteroidal object (magnitude ~19) on CCD images taken on Feb. 12.6 UT with a 0.5-m f/2 Schmidt reflector at Haleakala, Hawaii, in the course of the "Asteroid Terrestrial-Impact Last Alert System" (ATLAS) search program. This object has been found to show cometary appearance by CCD astrometrists elsewhere after the object was posted on the Minor Planet Center's PCCP webpage due to its orbit. The new comet has been designated C/2021 C4 (ATLAS).

We performed follow-up measurements of this object while it was still on the PCCP webpage.

Stacking of 5 unfiltered exposures, 90 seconds each, obtained remotely on 2021, February 22.2 from X02 (Telescope Live, Chile) through a 0.6-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 it for a bigger version; made with TYCHO software by D. Parrott):


Credit: Minor Planet Center
 

M.P.E.C. 2021-D113, assigns the following preliminary parabolic orbital elements to comet C/2021 C4 (ATLAS): T 2021 Jan. 21.04; e= 1.00; Peri. =  320.80; q = 4.50;  Incl.= 132.85


by Ernesto Guido

Tuesday, February 9, 2021

The Dig & Basil Brown's book on Star Charts

A recently (January 29, 2021) released film on the Netflix streaming platform, The Dig, tells the story of the 1939 excavation of Sutton Hoo, the exacavation of the great 7th-century Anglo-Saxon royal ship burial, considered one of the greatest archaeological discoveries in British history. It is a very interesting scientific and human story that will not fail to interest and attract many viewers. On the internet you can find accurate accounts of the events that occurred in Sutton Hoo and that saw as main protagonists local self-taught archaeologist-excavator Basil Brown and landowner Edith Pretty who hired him to tackle the large burial mounds at her rural estate in Sutton Hoo near Woodbridge. 

Credit: B. Brown

For astronomy enthusiasts like the readers of this blog, one of the most interesting facts is certainly that the protagonist of this story, Basil Brown, was not only an archaeologist but also an amateur astronomer. Brown (22 January 1888 - 12 March 1977) joined the British Astronomical Association on 27 November 1918. Through NASA ADS it is possible to find and read some of his astronomical notes and reports published on the BAA Journal (JBAA). 

For example he observed the transit of Mercury across the Sun on 7th May 1924 at Diss, Norfolk, with his only instrument a 2-inch (50mm) refractor (in the film you'll see Ralph Fiennes as Basil Brown carrying around a small telescope). His report to BAA was illustrated with four sketches: "the foregoing is an interesting illustration of the capability of a small telescope in the hands of an enthusiastic amateur".

He also observed meteors, the aurora and the zodiacal light. Basil was also searching for comets as reported in a Notes section of November 1921 of JBAA: "COMET NOTES. -- I have been glad to hear from Mr. Basil Brown that he has spent a good many hours in sweeping for comets. This should be one of the main objects of the sectional workers, especially when no known comets are within reach".

One of the facts that the viewer learns about while watching the movie The Dig, is that Mr. Brown is the author of an astronomy book, specifically a book on Atlases and Celestial Maps. In fact, while Mr. Brown never published any of his archaeological work, "the good reception which greeted his various astrono-mical papers led him to  publish in 1932 the book "Astronomical Atlases, Maps and Charts" a work which the publishers then described as  'filling an inexplicable gap in the literature'".

As it happens, I own a copy of the first edition of the book published in 1932 by Search Publishing Company in London (a reprint was published in 1966). and I think it's interesting to share here some photos of this beautiful book. (click on each image for a bigger version)

Credit: E. Guido

 

This is a book that should not be missing from the shelf of any fan of the history of astronomy (unfortunately it is quite difficult to find) and in particular of that fascinating branch that is the mapping of celestial things. The book, which as the subtitle says is a historical and general guide, is full of references and anecdotes about atlases, star charts and their authors.  As Mr. Brown points out in his introduction (a part is reproduced in the images below): "History is as essential to science as roots to a tree. Modern Astronomy may be likened to a great city built on foundations dating back so far as to be almost as old as the human race". There are also in the book illustrations of the most famous atlases and maps of antiquity. Some chapters are devoted to the mapping of the Moon, the Planets and the Sun.

 

 

Credit: E. Guido

Credit: E. Guido


There are several pages devoted to maps containing information and locations of comets of antiquity. The author provides a whole series of book titles that will help the comet scholar.


By Ernesto Guido

Friday, February 5, 2021

New Comet C/2021 B3 (NEOWISE)

CBET 4929 & MPEC 2021-C16, issued on 2021, February 04, announce the discovery of a comet (magnitude ~19) in infrared images obtained during Jan. 22 UT with the Near-Earth Object Wide-field Infrared Survey Explorer (or NEOWISE; formerly the WISE earth-orbiting satellite). The new comet has been designated C/2021 B3 (NEOWISE).

We performed follow-up measurements of this object while it was still on the PCCP webpage.

Stacking of 50 unfiltered exposures, 30 seconds each, obtained remotely on 2021, January 27.1 from X02 (Telescope Live, Chile) through a 0.6-m f/6.5 astrograph + CCD, shows that this object is a comet with a compact coma about 10" 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 it for a bigger version; made with TYCHO software by D. Parrott):


 

Credit: Minor Planet Center


M.P.E.C. 2021-C16, assigns the following orbital elements to comet C/2021 B3: T 2021 Mar. 11.18; e= 0.93; Peri. =  293.69; q = 2.15;  Incl.= 119.50


by Ernesto Guido

Saturday, January 30, 2021

New Comet C/2021 A1 (Leonard)

CBET 4907 & MPEC 2021-A99, issued on 2021, January 10, announce the discovery of a comet (magnitude ~19.5) by Gregory J. Leonard on CCD images taken on Jan. 3.54-3.56 UT with the Mount Lemmon Survey's 1.5-m reflector. The new comet has been designated C/2021 A1 (Leonard).

We performed follow-up measurements of this object while it was still on the PCCP webpage.

Stacking of 14 unfiltered exposure, 120 seconds each, obtained remotely on 2021, January 6.4 from H06 (iTelescope network, New Mexico) through a 0.43 m f/4.5 Reflector + CCD, shows that this object is a comet with a diffuse coma about 7" in diameter.

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


M.P.E.C. 2021-A99, assigns the following nearly parabolic orbital elements to comet C/2021 A1: T 2022 Jan. 3.3; e= 0.99; Peri. =  225.09; q = 0.6;  Incl.= 132.68

This comet has excellent brightness prospects for December 2021. In fact, before the perihelion on January 3, 2022, at a distance of 0.6 AU, comet C/2021 A1 (Leonard) will pass just 0.233 AU from Earth on December 12, 2021 and it will have an exceptionally close pass of Venus at 0.028 AU on December 18, 2021.

Comet C/2021 A1 (Leonard) could potentially become a naked-eye object. 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). (as always with comets, the future magnitudes reported here are only indicative). 


Below a graph showing the orbit diagram (made using the JPL Small-Body Database Browser) of comet C/2021 A1 (Leonard) and its position on December 18, 2021.


by Adriano Valvasori & Ernesto Guido


Tuesday, December 29, 2020

Follow-up of recent NEOCP from OASDG L07 - Part II

Below you can find a new selection (part I available here) of some objects for which we recently made follow-up observations at the "Osservatorio Salvatore di Giacomo, Agerola, ITALY" (MPC code L07; Observers E. Guido, A. Catapano, F. Coccia) while they still were on the NEOCP list. More details about the telescope, the  magnitude, number of images & exposition, asteroid speed & PA etc. are on the images. Click on each image for a bigger version. All the processing has been made with TYCHO software by D. Parrott.

COMET C/2020 V2 (ZTF), (neocp designation ZTF0G6I). Stacking of 25 unfiltered exposures, 120 seconds each, obtained remotely on 2020, Nov. 19.1 from L07 (Osservatorio Salvatore di Giacomo, Agerola) through a 0.5 m f/8 Ritchey Chretien + CCD, showed that this object is a comet with a diffuse coma about 7" in diameter and FWHM 3.3" compared to the average value of 2.1" for the stars of same magnitude.

 

2020 WH1 (neocp designation SaSza42) is an Apollo-type asteroid discovered by K88 GINOP-KHK, Piszkesteto, observer R. Szakats on November 17, 2020. This asteroid has an estimated size of 33 m - 73 m (H=24.6) and it had a close approach with Earth at about 11.5 LD (Lunar Distances = ~384,000 kilometers) or 0.029 AU (1 AU = ~150 million kilometers) at 0824 UT on 09 Nov. 2020.

 

2009 WY7 (neocp designation Sar2518) is an Aten-type asteroid (First observed at Lincoln Laboratory ETS, New Mexico on 2009-11-19) recovered by K88 GINOP-KHK, Piszkesteto, observer K. Sarneczky on November 22, 2020. This asteroid has an estimated size of 40 m - 90 m (H=24.1) and it had a close approach with Earth at about 20.17 LD (Lunar Distances = ~384,000 kilometers) or 0.05184 AU (1 AU = ~150 million kilometers) at 1104 UT on 24 Nov. 2020.

 

2020 WO3 (neocp designation C3ZZY12) is an Aten-type asteroid discovered by G96 Mt. Lemmon Survey on November 22, 2020. This asteroid has an estimated size of 67 m - 150 m (H=23.0) and it had a close approach with Earth at about 40.26 LD (Lunar Distances = ~384,000 kilometers) or 0.10345 AU (1 AU = ~150 million kilometers) at 1911 UT on 28 Nov. 2020.

 


 
COMET P/2005 CR16 = P/2003 WR168 = P/2020 W2 (NEAT-LINEAR) - (neocp designation C3XUF62). It is a comet discovered in survey images taken by Mount Lemmon Survey (G96) obtained on Nov. 16 UT. Subsequent follow-up astrometry and improved orbits allowed the MPC to find prediscovery positions and link the object to multi-opposition minor planet 2005 CR16 = 2003 WR168.

 

2020 WW3 (neocp designation C417PE2) is an Aten-type asteroid discovered by G96 Mt. Lemmon Survey on November 24, 2020. This asteroid has an estimated size of 20 m - 45 m (H=25.6) and it had a close approach with Earth at about 9.12 LD (Lunar Distances = ~384,000 kilometers) or 0.02344 AU (1 AU = ~150 million kilometers) at 0243 UT on 23 Nov. 2020.

 



 by Ernesto Guido

Tuesday, November 17, 2020

Follow-up of recent NEOCP objects from OASDG L07

Below you can find a selection of some objects for which we recently made follow-up observations at the "Osservatorio Salvatore di Giacomo, Agerola, ITALY" (MPC code L07; Observers E. Guido, A. Catapano, F. Coccia) while they still were on the NEOCP list. More details about the telescope, the  magnitude, number of images & exposition, asteroid speed & PA etc. are on the images. Click on each image for a bigger version. All the processing has been made with TYCHO software by D. Parrott.

2020 VX5 (neocp designation C3WZUQ2) is an Apollo-type asteroid discovered by G96 Mt. Lemmon Survey on November 15, 2020. This asteroid has an estimated size of 55 m - 120 m (H=23.4) and it had a close approach with Earth at about 29 LD (Lunar Distances = ~384,000 kilometers) or 0.074 AU (1 AU = ~150 million kilometers) at 1950 UT on 11 Nov. 2020.


2020 VN1 (neocp designation A10sCsG) is an Aten-type asteroid discovered by T05 ATLAS-HKO, Haleakala on November 10, 2020. This asteroid has an estimated size of 7.3 m - 16 m (H=27.8) and it had a close approach with Earth at about 1.19 LD (Lunar Distances = ~384,000 kilometers) or 0.00306 AU (1 AU = ~150 million kilometers) at 0757 UT on 07 Nov. 2020.



2020 VF1 (neocp designation X71128) is a Centaur-type object discovered by D29 Purple Mountain Observatory, XuYi Station on November 08, 2020. At the discovery time it was at about 9.7 AU from the Sun.


2020 VM1 (neocp designation P219ias) is an Apollo-type asteroid discovered by F52 Pan-STARRS 2, Haleakala November 08, 2020. This asteroid has an estimated size of 190 m - 420 m (H=20.8) and it had a close approach with Earth at about 73 LD (Lunar Distances = ~384,000 kilometers) or 0.18 AU (1 AU = ~150 million kilometers) at 2033 UT on 01 Nov. 2020.




by Ernesto Guido


Saturday, October 31, 2020

Discovery of a Nova in M31 - M31N 2008-12a

Just few days after the discovery of the nova in M31 designated as AT2020xyv, we report our discovery of another possible nova in M31 on a 240-s R-band CCD frame taken on 2020 Oct. 30.91 UT with the 0.5 m f/8 Ritchey Chretien + CCD FLI PL4240 at MPC Code L07 (Osservatorio Salvatore di Giacomo, Agerola, ITALY), with magnitude R = 18.48 +- 0.10 at coordinates: 

R.A. = 00 45 28.80, Decl.= +41 54 10.0 (equinox 2000.0; Gaia DR2). 

This transient PNV J00452880+4154100 has been independently discovered by Darnley et al. as reported on ATel #14130 of 31 Oct 2020; 07:32 UT and identified by them as the eruption of recurrent Nova M31N 2008-12a.


Our discovery image of this transient (click on it for a bigger version):


 

M31N 2008-12a is a remarkable recurrent Nova in the Andromeda Galaxy with the "shortest interoutburst time of any known recurrent nova. Since its discovery in December 2008 by two Japanese amateur astronomers, Koichi Nishiyama and Fujio Kabashima, a total of 13 subsequent outbursts have been observed. The mean time between observed eruptions (all observed between late August and December) is 364+/-52 days". 

by Antonio Catapano, Ernesto Guido, Luca Izzo