Comet C/2025 A6 (Lemmon) Nov 2 and ASTAP

November 2nd, 2025, both transparancy and seeing bad. So, no good images of Comet C/2025 A6 (Lemmon). Images stacked using APP and ASTAP. ASTAP was used to identify some object like Messier M10 & M12 aswell as two Asteroids. 

Setting: Nikon D7500 on Skywatchter Star Adventurer 2i

Software : APP, ASTAP, CS4 and DeNoise AI

Comet C/2025 A6 Lemmon

Open sky but a lot of dew resulting in moderate images of Comet C/2025 A6 (Lemmon).

Using ASTAP, area magnitude is 5,4... cool!

ASTAP - Astrometric Stacking Program

I'm working my next challenge: making a light curve of a variable star. I was reading an article in magazine Heelal (November 2025 - Review Dwarf3 by Dmonique Dierckx) which explained the making of a curve using the Dwarf3 and ASTAP. So I went searching for more information on this software.

Downlaoding ASTAP was done via this link https://www.hnsky.org/astap.htm

I also downloading the following databases : D80 and V50

ASTAP, Astrometric Stacking Program, is able to stack images; so far I was only able to do this with Fits files. On top of this, it makes annotations, deepsky, asteroids, comets and variable stars.

There is a section Photometry, which calculates the magnitude and compares those with the database. Using color images, ASTAP can extract the green channel which makes values more accurate. 

When analysing the image with M51, two variable stars showed up. I let the software extract the green channel and measuring the magnitude. This data was copied into excel making the curve. 

Comet C/2025 A6 Lemmon on Halloween evening

Haloween evening, October 31, 2025 during a bright interval I was able to image Comet C/2025 A6 (Lemmon).
This time I used my Star Adventurer 2i together with Nikon D7500, a set up which made it possible to track the comet for 60s.

Setting: Nikon D7500

Mount: Skywatcher Star Adventurer 2i

Exposure : 4x60s ISO800; 2x10s ISO3200; 2x10s ISO6400

Software: APP, CS4 and DeNoise AI

Comet C/2025 A6 (Lemmon) October 27

On the evening of October 27 ... a cloud free sky. So time to observe Comet C/2025 A6 (Lemmon).
I took a wide field using more then 260 images, each 5s.

The other images were taken with a larger focal point but with a time difference of one hour. Due to this time difference, the comet was low above the horizon resulting in fainting out of the tail.

Sun October 26

A small opening in the clouds and windy, but still I took my chance resulting in only one capture of the Sun. Some nice prominences at the east side.

Setting: Sol'Ex by James R, 2nd Gen Slit, ASI678MM, TLAPO80/480

Herschel Wedge

Tilt: -0,7° Sx/Sy 1,12

Software: SharpCap, JSolex, Inti, CS4

Comet C/2025 A6 (Lemmon)

Finally an open sky for about half and hour, which was enough to capture comet C/2025 A6 (Lemmon).

Setting: Nikon D7500 with 112mm f/5.3, ISO6400 and exposure time of 5s

No Guiding

Software: APP 2.0.0. beta29, DeNoise AI, CS4

APP: Normal and MAD regression Avg (8;2)

Discussion:

Brigth core with both dust tail and ion tail. Structure in ion tail with knots aswell with small and wider regions. Tail extends minimum 5° .

Volcano Crater Hrossaborg (Iceland) - Apollo & Oblivion

During our trip through Iceland, we also visited the Hrossaborg Crater.

Hrossaborg Crater is a volcanic crater located in northeast Iceland, near Lake Mývatn. It’s actually an old tuff ring, formed by explosive volcanic activity, est 10.000 years ago, when magma came into contact with groundwater. The crater’s walls rise sharply and form a nearly perfect circle, giving it an otherworldly appearance—especially when seen from above or across the surrounding lava fields.

Because of its dramatic, barren landscape, Hrossaborg has been used as a filming location for several productions that wanted to capture a “moon-like” or alien environment.


Oblivion (2013) – The sci-fi film starring Tom Cruise used Hrossaborg as one of its key shooting locations. In the movie, it served as a backdrop for the scenes involving the base of operations on the desolate Earth. The stark volcanic terrain helped create the illusion of a post-apocalyptic world.

Apollo Connection – While not directly related to the Apollo missions, the resemblance of Iceland’s volcanic landscapes (including Hrossaborg and nearby regions like Askja and the Highlands) to the Moon’s surface led NASA to train Apollo astronauts in Iceland during the 1960s. They practiced geological fieldwork here to prepare for moon exploration.

Reinstalling Astro Software using WIndows 11 (SharpCap, EQMOD, PHD2, ASCOM)

 

Screenshot with Sharpcam, EQMOD, PHD2

A couple of months ago I bought a more powerfull PC which also has W11. As a consequence I needed to reinstall all software to connect and work with my existing mounts and camera's.
Before I used mainly SharpCap and N.I.N.A. : SharpCap to polaralign and planet imaging. N.I.N.A. is used for deepsky imaging. Lately I'm using SharCap a lot for Solar Imaging and  found out more things can be done: feature tracking for imaging planets and the sun aswell as platesolving. I didn't use both of them but seems I need to get into this. 

In stead of installing N.I.N.A. I focussed on getting everything to work with SharpCap, meaning connecting the mount and my ASI Camera's.

At first following software was installed and/or updated with the last version:

- SharpCap 

- ASCOM 7.0.2

- PHD2 2.6.13

- EQMOD v200w 

After installing Synscan and setting up Ascom, the system requested to upgrade by firmware of the SynScan. I never did this before and thus the firmware of Synscan was upgraded to V4.42.

A dry run was done using:

- mount AZEQ6GT

- ASI Camera's: ZWO224MC and ZWO2600MC

- SharpCap

- Stellarium V25.2

- EQMOD

- PHD2

I used an external USB hub with 4 USB connections. The RJ cable from my SynScan was connected using an USB to the USB hub creating a serial COM 4 port. This can be checked using Devices of W11.

Baud speed was set on 9600 and after all connecting the dry run was performed succesful.

Below is my new workproces which still needs to be tested during a clear sky :)

Lecture by Dr. Marcel van Daalen

 

During the annual JVS/VVS weekend (October 4th), Dr. Marcel van Daalen of the university of Leiden gave a lecture on the current status of our understanding of the universum. He talked about historical facts, observations and aswell inconsistencies. 

Sol'Ex articles published in Magazine Heelal

My articles on Sol'Ex (a follow up article on the evolution of Sol'Ex and it's software)  and the observation of the E-Corona using my Sol'Ex are published in magazine Heelal.

Sun H-Alpha with active prominences September 29, 2025

 

On the North Eastern limb a free prominence and on the Mid Western limb a long prominence moving away to space... so very active prominences.
The image was processed using new JSolex 4.1.1

This CaIIH is a very sharp image taken with Solex by James R. and 2nd Gen Slit. 

Getting this sharp image is done with both:

- sharp edges

- camera sharpness

- collimator adjustment with focus on the dustlines; this seems working. 

H-alfa2cb

Setting:

TLAPO80/480 with ASI678MM and Solex by James R.

Herstel Wedge

Software: SharpCap 4, Inti 6, JSolex 4.1.1 and CS4

Tilt <0,2° and Sx/Sy 1,1

Seeing with SSM3 almost all day <1,5 arcs

Data submitted to ftp.obspm.fr SOLAP

Comet C/2025 A6 (Lemmon)

This morning I took some images of Comet C/2025 A6 (Lemmon). The comet is currently 1,1AU away from Earth and will be at closest on October 21, 2025 on a distance of 0,59AU. Perihelion transit will take place on November 8th. Max brightness is predicted between these two days with the Comet low above the horizon after sunset.

Setting: Nikon D7500 f/4 28mm ISO3200 4s.
Editing: CS4 and DeNoise AI

Artemis II Boarding Pass

Next year, April 2026, NASA plans Artemis II crewed mission around the Moon. I have already my Boarding Pass :)

Video Aurora 17092025

 

My images combined into a video of the Equinox Aurora in Iceland (Sandgeroi).
Images taken on Sept 17, 2025 with Nikon D7500 and 10mm Tamron Lens.

Halo from airplane

When preparing for landing in Iceland, I was able to make some pictures of a halo with our plane.

 

Aurora Iceland, Equinox Storm

My images of aurora in Iceland. These were caused by the equinox storms and were visibble over a couple of days.

Aurora Iceland

With a Kp 4 (or was it more?) we could observe polarlight in Iceland. Observation was done in Hellissandur near the Coast. Sky cleared up but with high clouds. Polarlight was visible as from 22h but kept going for a couple of hours. A certain moments the entire sky was colored green. Picture taken by my daughter with iPhone. So more pictures to come.

Rainbow @Skogafoss

Beautifull waterfall Skogafoss (Iceland) with a nice rainbow.

Rainbow above volcano crater

> When walking around Volcano Crater @Selfoss Iceland a supernumerary rainbow showed up creating a nice view and picture.
>

Apocalyptic Red Rainbow at Sunset

I could image a rainbow, only 9 minutes before sunset. The rainbow was quit red with aswell a red cloudy background. Very apocalyptic...

Sunspot AR4197

Sunspot AR4197 consists of about 50 spots and is 740MH big. Late afternoon clouds started to disappear and I installed my TAL200K. My parents were at home and I let them watch the big sunspot. Next I connected my ASI290MM camera and took some images. Seeing wasn't good which resulted in more then 500Gb of data. Stacking was done using AstroSurface but editing was done with IMPPG and CS4.

Setting: TAL200 f/8.5, barlow x2 and ASI290MM

Filters : ND5.0, IR/UV cut and OIII

Software: SharpCap, AstroSurface, IMPPG and CS4

 

Supernumerary Rainbow

This evening a double rainbow which was also a supernumrary one.

Image taken @Averbode - Belgium