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C/2024 G3 (ATLAS) - A bright evening comet for southern-hemisphere observers?

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#1 Exeligmos


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Posted 19 April 2024 - 11:15 PM

C/2024 G3 (ATLAS) could be a fine comet for southern-hemisphere observers. After passing perihelion at 0.09 AU on January 13, 2025, it will move southeast into the evening sky. As has happened with past comets, this could either fizzle near perihelion, or it could put on a dramatic show like C/2006 P1 (McNaught), or something in between.


More details at:



Epoch 2025 Jan. 5.0 TT = JDT 2460680.5                                         
T 2025 Jan. 13.44359 TT                                 Rudenko                
q   0.0935656            (2000.0)            P               Q                 
z  +0.0000120      Peri.  108.13072     -0.04066614     +0.81516642            
 +/-0.0000001      Node   220.35582     +0.14750825     +0.57683743            
e   0.9999989      Incl.  116.83545     +0.98822446     -0.05255750            
>From 87 observations 2024 Apr. 5-17, mean residual 0".5.


m1 = 9.0 + 5 log d + 10.0 log r

Edited by Exeligmos, 19 April 2024 - 11:35 PM.

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#2 yuzameh



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Posted 20 April 2024 - 09:06 PM

Given its orbit it's only brighter than mag 3 for around 11 days, with Solar Elongation of only around a dozen degrees at the two mag 3 points, around the 13th it is mag -1.3 ish but a mere five or so degrees from the Sun AND the Moon is only one days shy of being full (only five days from full at both the mag 3 points also, granted the latter waning phases likely not rising until the comet has set).  The observational arc is still short and the eccentricity may be tweaked a bit but the perihelion distance isn't likely to change meaningfully so the above isn't likely to change much in detail terms.


Compare that to seeing Mercury when near that brightness and near the Sun.


On the other hand there was a classical telescope times comet and one recently (this century) where the tail could be seen above the horizon after sunset (I remember a marvellous photograph of the latter from South Africa).


On the other other other hand remember ISON.  I haven't checked my memory but I don't think ISON managed to survive to perihelion, hence disappointed for that reason.

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#3 BrooksObs



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Posted 21 April 2024 - 01:59 PM

The disappointing fact regarding this object is that given that the comet's currently assumed absolute magnitude (Ho) is only +9.0 and that the orbit indicates it to essentially be a "new" comet, C/2024 G3 has absolutely no chance of surviving perihelion passage. More than likely, it won't even last long enough to even approach to within half an AU of the Sun before fading out totally.



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#4 luxo II

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Posted 21 April 2024 - 08:32 PM

It won’t survive perihelion. 

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