SOHO SWAN COMET C/2023 P1 NISHIMURA

 Comet C/2023 P1 NISHIMURA.

SOHO/SWAN/J.P.Navarro Pina.

The Ly-α emission is the UV emission, this is more intense in comets, the water ice in the comet's nucleus evaporates as the comet approaches the Sun, the effect of solar ultraviolet radiation decomposes the molecules of water, H2O, and the released H atoms glow with ultraviolet light. According to my calculations, the rate of water production on the comet is 10^29.5 mol s, this represents a rate greater than 3,000 kg s. Possibly today, the date of perihelion has exceeded that limit of water production, reaching 4 or 5,000 kgrs s. In the attached gif, the intensity of the H atoms in the comet's coma is observed, a product of photodissociation by fluorescence. due to the interaction of UV radiation from the solar wind, much higher than 1.06 in the attached image.

SWAN obtains almost daily all-sky images of the Lyman-α distribution of interstellar hydrogen, which provides information about the solar wind, and the ultraviolet radiation, which devours it, through ionization and exchange of electrical charges, in this way, You can observe the hydrogen comas of comets, when they are bright enough, as in the case of Nishimura. Based on these images, the real water rate of the comet can be calculated and verified with that obtained by theory.

Calculations of physical parameters of comet C/2023 P1 NISHIMURA

The new estimated nuclear radius of the comet is RN = 0.75 +/- 0.02 kms.

The active area fraction of the core surface is (F)+/-o= 1.4+/- 0.0

Its estimated mass is log10 M(n) = 11.6

Its maximum water production rate is Log Q (H2O) > 3,000 kgrs /sec or 10^29.50 mol s

Power law R(-3.4)

Absolute Magnitude Nuclear R BandRN ( 1,1,0 )=+18.23

Calculations based Sosa Fedz 2011

ANALYSIS LIGHT CURVE C/2023 P1 NISHIMURA

 

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.