Solar&Planetary LtE Now for CMO/ISMO in June 2023

Solar & Planetary LtE Now in June 2023

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LtE in May 2023

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¤••••• Subject: Mars: June 30, 2023

Received: 1 July 2023 at 05:03 JST

Hi,

I have attached my latest image of Mars June 30, 2023 at 00:04 UT.

https://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2022/230630/FMl30June23.png

Thanks,

Frank J MELILLO (Holtsville, NY)

¤••••• Subject: Saturn 2023-06-17 UT

Received: 27 June 2023 at 19:18 JST

Saturn IR image on 26 June 2023.

Best regards,

Tomio AKUTSU (Cebu, PHLIPPINES)

Cebu Observatory

¤••••• Subject: Jupiter 2023-06-26 UT

Received: 27 June 2023 at 15:06 JST

Jupiter images on 26 June 2023 UT

Best regards,

Tomio AKUTSU (Cebu, PHLIPPINES)

Cebu Observatory

¤••••• Subject: Jupiter 2023-06-25 UT

Received: 26 June 2023 at 15:11 JST

Jupiter images on 25 June 2023 UT

Best regards,

Tomio AKUTSU (Cebu, PHLIPPINES)

Cebu Observatory

¤••••• Subject: The colors of Jupiter in 2022 (3)

- Photometric spectra of individual features

Received: 25 June 2023 at 22:19 JST

Hi all,

This is the last part of the work. Photometric spectra like these are more suited to study smaller regions like spots or belts. Some interesting developments took place in comparison with 2021.

1) The GRS has reddened again, although probably not to the level it had prior to the brightening of 2021. Its U and B albedos are inferior to that of the whole globe. It dimmed also in the V band, but not in R and I. This is the translation of the "redder" color! Interestingly, the methane albedo of the spot look to have increased, from 0,119 to 0,126 at 890 nm, and 0,32 to 0,35 at 1000 nm (mixed band with continuum). HST Scientists have noticed during the period 2015-2020 that there was a correlation between the reddening, the darkening in UV, and the brightening in CH4 ; and this looks to have been the case in 2022 as well.

2) The EZ has noticeably brightened. I have also found a small increase in the short wavelengths during the course of the apparition, from late August to late October. Judging by its aspect on the first images of the current 2023 apparition where it looked to have kept on brightening/whitening, it may be a real change.

3) The graphs also depicts the wider changes affecting the main belts and zone, as seen already on the North-South scans.

Unfortunately I did not observe oval BA last year, but maybe I could work with someone else data, I will check this...

Regards,

PS I can make graphics for other regions if needed !

Christophe PELLIER (Nantes, FRANCE)

Planetary astronomy and imaging

¤••••• Subject: Venus 2023-06-24 UT

Received: 25 June 2023 at 10:18 JST

Venus UV mages on 24 June 2023 UT

Best regards,

Tomio AKUTSU (Cebu, PHLIPPINES)

Cebu Observatory

¤••••• Subject: Jupiter 2023-06-23 UT

Received: 24 June 2023 at 17:37 JST

Jupiter images on 23 June 2023 UT

Best regards,

Tomio AKUTSU (Cebu, PHLIPPINES)

Cebu Observatory

¤••••• Subject: Mars 23rd June 2023 RGB and IR

Received: 24 June 2023 at 16:56 JST

Hi,

Mars in fleetingly good conditions last night. RGB and IR images. Details on the images,

https://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2022/230623/MLw23June23.png

Best wishes

Martin R LEWIS (St. Albans, Hertfordshire, the UK)

¤••••• Subject: Jupiter 2023-06-20 UT

Received: 21 June 2023 at 11:46 JST

Jupiter images on 20 June 2023 UT

Best regards,

Tomio AKUTSU (Cebu, PHLIPPINES)

Cebu Observatory

¤••••• Subject: Mars 19th June 2023

Received: 21 June 2023 at 08:00 JST

In difficult conditions last night, an IR image and an (IR)GB image of Mars at 4.4"
Details on the images

https://www.kwasan.kyoto-u.ac.jp/~cmo/cmons/2022/230619/MLw19June23.png

Cheers

Martin R LEWIS (St. Albans, Hertfordshire, the UK)

¤••••• Subject: Jupiter 2023-06-18 UT (Color, UV, CH4, IR)

Received: 20 June 2023 at 19:59 JST

Jupiter images (Color, UV, CH4, IR) on 18 June 2023 UT

South is up.

Best regards,

Tomio AKUTSU (Cebu, PHLIPPINES)

Cebu Observatory

¤••••• Subject: Jupiter 2023-06-18 UT

Received: 19 June 2023 at 19:19 JST

Jupiter images on 18 June 2023 UT

Best regards,

Tomio AKUTSU (Cebu, PHLIPPINES)

Cebu Observatory

¤••••• Subject: Saturn 2023-06-17 UT

Received: 18 June 2023 at 20:12 JST

Saturn images on 17 June 2023.

Best regards,

Tomio AKUTSU (Cebu, PHLIPPINES)

Cebu Observatory

¤••••• Subject: The colors of Jupiter in 2022 (2)

- North-South scans and color indices

Received: 18 June 2023 at 18:09 JST

Hi all,

Here is the second part of the work!

In 2022, several important color moves have been observed on Jupiter, the most important ones being:
- The brightening of the EZ, that has past from deep orange to yellow. Its albedo rised from 45% to more than 60% in blue light. However, last year it still did not reached its brighter state (this could be for the coming apparition, by looking at the first images). The change is also important in that region on the B/U color index, which is nice to detect special "red" coloration events, but not so in CH4 (although a slight dimming is maybe observed).
- The brigtening of the NTB ("fade")
- And a large darkening and reddening of all equatorial, tropical and first temperate south latitudes (EZ, NTrZ, STB somewhere)

But other changes can be observed. Inspired by the Jupiter work performed by Antonio Cidadao, Steve Hill and Barry Adcock, I have begun to play with images math operation and you can find one here. The substraction of equatorial strip maps from the two years, on psf-processed and LD compensated images is producing a nice binary color code for both albedo changes and color shifts.

All scans display the previous value from 2021 in dashed line. Not a surprise, you can see that the changes are becoming gradually muted when the wavelength increases, and they become almost undectable in infrared.

I have added a CH4 profile including the GRS. There will be more to discuss on the color of the GRS but this will be for the next message, that will send the photometric spectra of some individual features or regions.

best wishes

Christophe PELLIER (Nantes, FRANCE)

Planetary astronomy and imaging

¤••••• Subject: Jupiter 2023-06-17 UT

Received: 18 June 2023 at 14:00 JST

Jupiter images on 17 June 2023.

Best regards,

Tomio AKUTSU (Cebu, PHLIPPINES)

Cebu Observatory

¤••••• Subject: Saturn 2023-06-16

Received: 17 June 2023 at 16:56 JST

Saturn image on 16 June 2023.

Best regards,

Tomio AKUTSU (Cebu, PHLIPPINES)

Cebu Observatory

¤••••• Subject: Jupiter 2023-06-16

Received: 17 June 2023 at 16:13 JST

Jupiter image on 16 June 2023.

Best regards,

Tomio AKUTSU (Cebu, PHLIPPINES)

Cebu Observatory

¤••••• Subject: Saturn 2023-06-13

Received: 14 June 2023 at 12:34 JST

Saturn images on 13 June 2023.

Best regards,

Tomio AKUTSU (Cebu, PHLIPPINES)

Cebu Observatory

¤••••• Subject: Jupiter 2023-06-12

Received: 13 June 2023 at 14:49 JST

Jupiter image on 12 June 2023.

Best regards,

Tomio AKUTSU (Cebu, PHLIPPINES)

Cebu Observatory

¤••••• Subject: The colors of Jupiter in 2022

- Albedos of the planet and photometric images

Received: 12 June 2023 at 16:33 JST

Hi all,

Please find attached the first results of my jovian color analysis from the past opposition. As last year, I am going to send 3 messages since it is a lot of work and data! Here are the global results, will follow the north-south profiles (2nd) and photometric spectra of individual features (3rd).

I am attaching a bunch of photometric images of the GRS hemisphere, the opposite hemisphere, and RcVB colors ; they have been psf-processed because I find that the psf views greatly enhance the view of details and contrasts without adding artefacts or over-contrasts like in the fully processed usual images. Of course, all analysis are performed on purely photometrics one (stacked, unfiltered).

Methods

The methods I have used have changed a little bit from 2021. I have again used the "galilean moons reference method", but stlightly less. Results were a bit less good than in 2021, just confirming for me that Europe is the best reference, and that the method does not look to work for the U band.

To the contrary of 2021, I have had more success with the star photometry method. I am still walking over a partially non orthodox path, but I hope to improve again for the next opposition. My method implies to take 3 stars (blue/yellow/red) in every bands, and manually adjust the color transformation coefficient so that the magnitudes of the yellow star are found from both the red and blue with the same values, and then using those values on the planet from the 3 stars. Results from last year on other planets shew that it does work although I would hardly be able to explain why (this is for example how I found my Mars magnitudes from December 9th, 2022).

Magnitudes for the IR bands come essentially from results for the nights of October 6 (results has been sent previously), and in UBVR from November 9 (unsent, I have just been lazy).

Results

The geometric albedo of Jupiter is found to be unchanged from 2021, except for U (35% to 37%) and Ic (41% to 39%). While it could come from a real change, I think that this is the result of inaccuracies or errors from the 2021 results, especially for Ic, since I don't think that the planet could lose 2 points of albedo in that band. Results for the north-south scans support this idea.

While it may be surprising that the values remain unchanged since there have been some notable evolutions, the comparison of the scans (2nd message) look to reveal that there have been a kind of "compensation" between the EZ (that has brightened again) and the southern latitudes (dimming either due to real changes or to the decreased polar axis tilt?).

I did not include results from the z' band this time, they are still quite incoherent, moreover, it is not really interesting for the study, being too wide and not different enough in aspect from the Ic band.

I will describe more about the color changes in the next messages, but I have successfully for example measured the brightening of the EZ as well as the reddening of the GRS :)

Sorry for the long message, and have a nice day!

Christophe