UPDATE AND NOTICES FROM POST-PERIHELION

 After a possible second outburst of comet C/2022 E3 ZTF and a possible transition of predominant volatile change to Water, the comet is currently at an apparent mean visual magnitude of +5.5. In previous posts, I commented on the possibility that it did not exceed magnitude m1=+6, but an unforeseen second outbursts has increased its magnitude by an average of +0.5 more than expected. A first outbursts in T-11 days, and a second outbursts in T+6 days, with respect to perihelion, it is logical to think that the light curve should be symmetrical with respect to perihelion, but this is true in very few cases, my This hypothesis proposes that the axis of rotation is tilted with respect to the cometary orbital plane , which means that the comet nucleus is exposed to different hemispheres before and after perihelion , if the two cometary hemispheres contain different amounts of dust and gas the rates of gas and dust emission is also logical to vary and therefore its light curve.
Graphic : COBS.

POSSIBLE OUTBURTS COMET ZTF

 My last analysis of the light curve based on the data offered by the COBS database, and using only visual magnitudes, filtering and subtracting the cdd, shows a possible second outbursts of comet C/2002 E ZTF, possibly +0.8 magnitudes visuals, near perihelion the comet has had a very interesting photometric behavior, around the end of December it showed a timid first outbursts of +0.5 magnitudes, near perihelion on January 12, 2023, the comet under its increase in brightness, turning off the gas and dust activity in the comet , with a much slower rate and an index with values close to 4.0 , and making it clear that the comet could not exceed +6.0 as maximum visual magnitude , now , the comet has suffered another possible burst of brightness, close to +0.8 visual magnitudes, which makes us grow optimistic, thinking of a maximum visual magnitude of +5.0 for February 2, the date on which the comet will be closest to Earth and much brighter.
The second reduced light curve shows more clearly the two outbursts of comet ZTF , the time interval between them could reveal a rotational phase of precession of the comet of approximately 17 days

REDUCED LIGHT CURVE C/2022 E3 ZTF

NEW REDUCED LIGHT CURVE C/2022 E3 ZTF

 Some new calculations that I have made of the comet C/2022 E3 ZTF , based on the formulas given by Sosa & Fdez ( 2011 ) , the maximum water production of the comet would reach 1 ton per second , using the formula log Q ( H2O ) = 30.53-0.234 * mred , the maximum reduced magnitude is mred = 8.7 , gives log Q ( H2O)= 10^28.5 mol/s .

Another calculation, using log D ( km ) = 1.5-0.13*m0 , yields an approximate nuclear radius of Rn=0.75 +/- 0.10 , and a possible active fraction area of f(A)=1.4 +/-0.1 , its estimated mass in log M ( kg ) = 10^12.1 .

I have reduced the COBS visual only light curve data, where I have reduced the magnitude and used the distance R , a decrease in the rate of increase in brightness is clearly observed, and its activity index (n) , with which Its photometric-visual formula changes, in this case, my hypothesis indicates that it would not exceed a maximum visual magnitude of 6.0 by the beginning of February.

LIGHT CURVE ZTF IN SKY AND TELESCOPE

Thanks from here to Bob King and Sky and Telescope magazine for naming my latest work on the Comet Light Curve C/2022 E3 ZTF. 

https://skyandtelescope.org/astronomy-news/spot-circumpolar-comet-ztf-c-2022-e3-in-binoculars/

REDUCED LIGHT CURVE C/2022 E3 ZTF

 Some additional comments the reason for the maximum visual magnitude of +7.5 is because the green line marks the adjustment of the ccd-only observations, since although the visual ones have also been added, the best adjustment due to the large number of ccd observations is 7.5 As a maximum magnitude ccd , this adjustment is exact , because the average difference between visual and ccd measurements is 1.5 magnitudes , therefore if we subtract 7.5-1.5 = 6.0 , for visual , as the maximum magnitude for early February .

Here i show the reduced light curve of the comet ZTF, all visual and ccd observations have been plotted, clearly at R=1.1 au, there is a decrease in the rate of increase in brightness of the comet, possibly due to a change in the predominant chemical volatile typical of new comets coming from the oort cloud, I have also calculated a maximum rate of water production of 1000 kgrs / second based on the formula of Sosa & Fdez (2011)

  log Q = 30.53-0.234*mred

Update Light Curve C/2022 E3 ZTF

 Update the light visual and ccd curve of comet C/2022 E3 ZTF based in 2.509 observations from MPC DATABASE This is the largest light curve of this comet to date and is based on the sum of ccd and visual observations obtained from the MPC DATABASE ( 2.509 ), it is possible that the comet has suffered a slowdown in its rise in brightness and that at most it can reach a maximum visual magnitude of +6, the comets as in this case "new" coming from the oort cloud from heliocentric distances of r=1.4 au onwards due to processes and changes in the sublimation of gases from the nucleus they suffer a brightness blackout that is already being noticed in the visual light curve, perhaps a change in the predominant chemical volatile is the cause.

UPDATE LEONARD COMET

 Comet Leonard quickly loses brightness, based on the latest visual observations of this comet, its latest report, is located at visual magnitude m1 = + 4.8, this means a rapid decrease in its rate of increase in brightness, and therefore in its gaseous and dusty activity, according to my calculation at a rate of 0.44 magnitudes per day, this is an excessive rate of decrease in brightness, after the burst of brightness, which took place a few days ago, specifically on December 14, Today the 19th, that is, 5 days later, the comet has lost 2.6 magnitudes, let's bear in mind that a jump of one magnitude is equivalent to a difference in brightness of 2.5 times (the fifth root of 100), so The comet in just 5 days, has varied approximately 6 times its difference in brightness, we can conclude that its period of visibility with the naked eye has been very short, according to my data, little more than a week ... however, it is still right now as bright as the comet 1 P / Halley in its appearance in 1986, I encourage all of you to keep trying to observe it, now that it is still relatively bright, remember, that it is already difficult to see comets of magnitude 5 as it is right now. Graphic : COBS .
https://fb.watch/9_SXErxymp/

Images of comet C/2021 A1 LEONARD .

 Images of comet C/2021 A1 LEONARD .

LARSON SEKANINA FILTER LEONARD COMET

 Good morning before the doubts that this comet is offering, and the rumor that runs that it is disintegrating, I have used the larson sekanina filter, this filter calculates the radial and rotational gradient of an image. It is used to enhance the finest details in bright objects, exhibiting symmetry of revolution (elliptical galaxies and comet commas). This filter is very powerful to reveal internal details within the coma of bright comets (such as jets and shells), in the attached image not a single fragmentation detail is observed, only the ionic tail, in addition to that I have done to ensure even more, a GDP of the coma, in which there is no abrupt or strange change in it.

Image Credit: Pepe Manteca.

Processed: J.P. Navarro Pina.

Dall-Kirkham Telescope 0.43 mts.

Cometary blackout in Leonard's Comet

 I have a hypothesis that I have been studying for years for these

cases, when a comet suffers a fading of the rate of increase in
brightness, and that is that the comet suffers a change in the

predominant volatile component CO -> H2O, this is usually typical in
the new comets coming from the Oort cloud, this slowdown in its
activity index, usually occurs in the heliocentric range of 1.5 <R
1.2, as is the case of comet C / 2021 A1 LEONARD, I do not think it
will increase much plus its brightness, since my last analysis
indicates an index n = 2.24, the term 2.5 n log R, represents the
change in brightness due to the variation of the heliocentric distance
of the comet, and the brightness varies by pure reflection n = 2, as a
solid object without gaseous activity, which I call the '' cometary
blackout '' .

Graphic adapted by COBS , Analysis J.P.Navarro .

NO FRAGMENTATION COMET 2021 A1 LEONARD

 I have just carried out an analysis of the brightness intensity profile of the coma of comet C / 2021 A1 LEONARD, and no apparent rupture or fragmentation is observed at the coma level, we await more observations that can confirm this fact .
Image Credit : Pepe Manteca
Processed : J.P.Navarro Pina