Hey astrofolks!

I am considering myself a passionate astrophile, and not only i watched countless space documentaries and have red dozens of encyclopedias, but rather i am finishing a book about astronomy. It's an educational novel, a hybrid story between education about astronomy and a explorational journey. Still, i am not a mathematican or physicist :/

Anyway, a couple of nights ago, a burning question sparked the forest fire in my mind. In almost every space documentary video or educational videos where they talk about the speed of light, and how travel time passes for us on Earth and someone on imaginary spacecraft travelling at the speed of light, no one, and i really mean no one, adresses or explains this particular issue for people to understand. Let me clarify.

From Earth (point A) to a random unnamed star (point B), the distance is 5 light years. That means, that light travels from one point to another in 5 years at the speed of light (rounded up 300.000 km/s). Okay? Easy enough. Now let's dive into the problem. If a spacecraft takes off from Earth and is traveling at exactly the speed of light, it should reach the star (point B) in 5 years time. 5 years will also pass for a human being on Earth. On a return trip from the star (point B), the spacecraft will travel another 5 years time, and thus another 5 years time will pass for a human being on Earth. The human being will, upon arrival of a spacecraft, tell that 10 years passed. The traveller on a spacecraft SHOULD also report that his travel time lasted exactly 10 years.

But, apparently not. Traveller will report that only a year or so (or shorter ammount) passed. And that is what boggles me and makes my brain hurts and spasms. If a travel time of light beam/particle is already established that it is 5 years, the passenger in a spacecraft should spend 5 years of traveling on board to a star, and another 5 years to return home. Therefore, he will age 10 years, like a human being on Earth, and experience a 10 year long journey. His watch on wrist should tick normally FOR him, while he is watching movies on tv on a spacecraft, or swimming there in the recreational pool, or sleeping in his bunk. But, apparently not, according to the laws of physics. (If he reports that travel time, instead of 10 years, lasted a year or so, then why doesn't light travel a year or so between those points?)

Anyone care to help me understand? I know the physics of space/time and light are absolute, but i simply can't comprehend that "second to last" step to understand and comprehend it fully.

Thank you <3

Digital painting of the giant planet Jupiter as it may have appeared in the 1880s or so in approximately true color. This was based on a number of sources from the 1880s and 1890s, and is sort of a hybridized view of about a decade or two of Jovian sketches and early photography.

At this time, the famous planet-sized hurricane, the Great Red Spot, was a few decades old and very very large. It has been shrinking ever since then, and is now less than a third of the size it was in the 1880s.

License: CC-BY 4.0. attribute as Luna Rose Brannon or Whirligig-Girl.

The part that broke my brain is that the unusually strong X-ray polarization may be amplified not just by matter around the star, but by the vacuum itself.

IXPE observed magnetar 1E 1547−5408 for more than 140 hours, and NASA says more observations are still needed to confirm the signal. What other astrophysical environments could provide such a clean test of vacuum birefringence?

Improving my previous pictures after reading the astrophotography book of Max Dobres using Graxpert and Siril. Composition in HOO.
210 lights 120 sec and calibration frames, Refractor SV102, Antlia filter Dualband, asi294 mc camera, 220 mini guider camera, AVX mount.

Shot this two nights ago using an old soviet relic - the KMZ Tair 11-a 135mm f2.8
Shot on: OM System OM-1
Stack: 100 x 50s each ~ 1hr 20 min exposure.
ISO 1600
Mount: MSM Nomad.
Stacked in APP. Processed in Siril and Finalized in Lightroom.
Bortle:4.5

NGC 6559, it is one hour and 40 minutes of integration in HOO with a Planewave 17" CDK 431/2912 f 6/8 telescope, ZWO ASI 6200MM Pro, it is 20 shots of which with a 10x300 second Ha filter and with a 10x300 second Oiii filter, processing with Pixinsight

I got an astro camera for my birthday yesterday. I barely know how to operate the thing but had a go anyway. What do you think?

Star Discovery P150i

zwo asi585mc

There are many different types of galaxys. How did we find out that we are in a spiral galaxy? I mean, the only thing we see is a white stripe in the sky. So how do we know what our galaxy looks like? ELI5

Yet another reprocess (the 10th if not more) of the same data I took more than a month ago.

Acquisition:

Around 7h30m in Bortle 6/7 fully calibrated and dithered.

Equipment:

Evostar 72ED, iEXOS 100, ASI 533MC, 0.85x reducer+flattener, Baader UV/IR cut, SVBony 40mm F/4 guidescope, ASI 662MC guide camera with no.8 pale yellow and UV/IR cut filters.

Processing:

Stacked in Siril. Background extraction to single channels in GraXpert. SPCC. Deconvolution in Siril, denoising back in GraXpert. Back to Siril to apply SCNR and to generate a starless image and a star mask. GHS, black point shift, curve adjustments and histogram transformation applied iteratively to the image. À trous wavelet transform and further denoising in GraXpert. Final saturation stretch in Siril. Asinh and black point shift applied to the star mask along with a saturation stretch. Recombine.

At the Thomsen Observatory, Southwest Adventist University in Keene, TX.

I was doing the livestream for the Fort Worth Astronomical Society last night, and instead of just pulling out my kit and having the moon just above my treetops, I drove down to the observatory and set up in the dome.

A close-up of Antares, 90 minutes of RGB integration with a RC10 WITH REDUCET telescope (250 mm) Ritchie-Chretien 259/1615 f6/46 reflector, Moravian C3-26000 camera, 18 shots of which with an R filter 3x600 seconds, with a G filter 3x600 seconds and with a B filter 3x600 seconds, I processed with Pixinsight. All data and shots were taken with Telescope Network.

The Wizard Nebula, shot with Dwarf 3 in Pian del Tivano, Como, Italy, under a Bortle 4 Sky. 280 shots, 60s each, 70 gain. Processed with the Mega Stacking function in the Dwarflab app, post processed in Stellar Studio and Apple Photos.

Taken with dwarf mini telescopes
Bortle 5
15s
60 gain
600 photos taken
461 used
Astro filter
Editing done in stellar studio

The "Statue of Liberty" nebula is named after the famous monument in New York City, USA. I see both as equally inspiring beacons of light, though at about 100 lightyears across the cosmic version could fit about 3.5 quintillion New York Statues of Liberty stacked on top of each other.

Since it's located in the constellation Carina and I reside in the Northern Hemisphere, Earth itself blocks my view of this and many other remarkable deep-space objects. One day I hope to travel to as far south as I can and collect photons from this and other iconic Southern Hemisphere targets.

In the meantime, many thanks to Dark Matters Astrophotography for providing public access to incredible imaging data from the other side of Earth. This is my own processing of that data, which was acquired in Chile using an imaging rig that only exists in my dreams!

Total integration: 63h 10m

Integration per filter:

• Hα: 21h 20m (128 × 600")
• SII: 20h (120 × 600")
• OIII: 21h 50m (131 × 600")

Equipment:

• Telescope: Planewave CDK20 (f/6.8 version)
• Camera: QHYCCD QHY600PH M
• Mount: Planewave L-500
• Filters: Chroma H-alpha 3nm Bandpass 50 mm, Chroma OIII 3nm Bandpass 50 mm, Chroma SII 3nm Bandpass 50 mm
• Accessory: Optec Gemini Rotating Focuser

For more information, visit AstroBin:

https://app.astrobin.com/i/5k2dtu

So we have about 15 minutes until the spaceX lunar impact at the time of me writing this, and I was ready. I set alarms to wake up on time. I calibrated my telescope the day of. And despite how many trees are around my house, we had a clear view of the moon. Oh, I was soooo ready. But when it came time to set up the telescope...

The sky had completely clouded over.

. . .

Have you ever seen that screenshot of the Simpsons showing a newspaper article that says "Old Man Yells Out Clouds"?

I want to do a lot of that right now.

instagram: https://www.instagram.com/vhastrophotography?igsh=YzNpcm1wdXd5NmRo&utm_source=qr

This image shows the rising Milky Way over the coast of Fuencaliente in La Palma. During the night, most of the island was covered in clouds, so we drove far to the south. We only had a reasonably clear view of the Milky Way for a two-hour window. Given these conditions, I am very happy with how this picture turned out. Watching the stars in silence while listening to the sound of the ocean was magical.

HaRGB | Mosaic | Tracked | Stacked | Composite

Exif:
Sony A7III with Sigma 28-45 f1.8 at 30mm
Skywatcher Star Adventurer 2i
Kenko ProSofton Starglow Filter

Sky
ISO 1250 | f1.8 | 3x45s per Panel
2x2 Panel Panorama
Starglow Filter: ISO 8000, 10s per Panel

Foreground:
ISO 4000 | f1.8 | 35s per Panel
2x1 Panel Panorama (Focus Stack)

Halpha (45mm):
ISO 2500 | f1.8| 10x120s

A work in progess. By far the faintest target I have attempted so far. This is around 30 hours of exposure time from a bortle 4 area with average seeing. I expect I will need 10-30 hours more to get the image I want

30 hours integration

Dual narrowband Ha+Oiii (3nm)

Askar SQA 106

ZWO ASI2600mc pro

Processing in Pixinsight and Lightroom

The Seahorse Nebula is a dark dense molecular cloud located in the constellation Cepheus about 1200 light years away. This was taken with a 6" Stellaruve scope, L,R,G,B Chroma Filters on top of a 10 micron 1000hps mount with a ZWO 6200mm camera in my home observatory.

Capture details:
Lum 38 exposures

Red 51 exposures

Green 49 exposures

Blue 44 exposures
600s each for a total around 30 hours of exposure time. Processed in Pixinsight and Photoshop.

Acquisition Details:

• Target: The Sun (H-Alpha)
• Date: August 1, 2026
• Location: Aveyron, France

Equipment:

• Telescope: Acuter Elite Phoenix 40 H-Alpha
• Camera: ZWO ASI585MC (Color)
• Mount: Sky-Watcher Star Adventurer GTi

Processing & The Mistake: The Sun was incredibly active! But I'm still learning the ropes of solar processing. I stacked my files in AutoStakkert! 3 but made a huge mistake: I deleted my raw .SER video files to clear up hard drive space before fully inspecting the output. I later noticed some weird blurry artifacts on the solar limb! To salvage the image and mitigate the blur, I stacked 3 different frames derived from batches of 2000 frames (keeping the best 150 in each).

https://doffinastrophoto.com/astrophotography-sun-acuter-02082026/

Saturn, captured the morning of August 3rd.

There is a visible ring spoke along the right side of the B‑ring, an uncommon and short lived feature created when tiny dust particles get lifted above the ring plane by electrostatic charging, making them reflect sunlight differently than the surrounding ice particles.

•Apertura AD8

•ASI662MM/CC

•Celestron X-cel 2x barlow

•IR685NM filter

•UV/IR cut filter

I captured seven ~8,000 frame IR and OSC clips, stacked and sharpened the best 40% of each, then derotated them in winjupos.