Starship Asterisk*

Above+Beyond wrote: ↑Thu May 04, 2023 8:38 pm Crazy as it sounds, someone is taking the null H-alpha observation as an indication that the oxygen must be pure, meaning it has an artificial origin -- namely it's all the oxygen lost by Apollo 13 some 50+ years ago.

This puts the cloud quite close, so there are at least two kinds of parallax measurements suggested which would at least rule out this possibility; they might already be present in the data but were not noticed because of smearing due to all the stacking.

See: VISNS.NeoCities.org/O-III_cloud_M31.html for more details.

OgetayK wrote: ↑Sun Feb 05, 2023 11:48 pm

VictorBorun wrote: ↑Sat Jan 21, 2023 3:21 am

OgetayK wrote: ↑Fri Jan 20, 2023 5:36 pm I'm curious about this red Hα halo around Andromeda. Not to mention previous works, the following comparison has a significant part missing. Maybe the photographers can explain if this is caused by postprocessing (maybe DBE?).
Image 1: https://ibb.co/cX6Lqnz
Image 2: https://ibb.co/6N1c1Ny

Sorry, what is DBE?
Does it imitate changing clouds in 2022 to 2023 APOD like this?

Click to view full size image 1 or image 2

Unexpected Clouds 2023.pngUnexpected Clouds 2022.png

...

DBE is Dynamic Background Extraction tool in PixInsight. Which is normally used for galaxy/nebulae surrounded by dark background. You manually define the "background" --which is supposed to be just dark sky-- so that any uniformity issues on the image are eliminated (say that left side of the image is brighter due to the light rises from the ground, it removes that). But if you mistakenly select the area where actually there is a cloud data, you remove that too. It's hard to predict because it smooths out to surrounding spots a lot. From your images, you can see most of the structures overlap and there is actually no structural change but some of the bright backgrounds like Ha areas are gone. However, I'm not sure. I'm just hypothesizing. This needs to be answered by the person who processed the image. I believe especially the halo around Andromeda is gone because of processing to reveal the Ha structures within Andromeda.

VictorBorun wrote: ↑Sat Jan 21, 2023 3:21 am

OgetayK wrote: ↑Fri Jan 20, 2023 5:36 pm I'm curious about this red Hα halo around Andromeda. Not to mention previous works, the following comparison has a significant part missing. Maybe the photographers can explain if this is caused by postprocessing (maybe DBE?).
Image 1: https://ibb.co/cX6Lqnz
Image 2: https://ibb.co/6N1c1Ny

Sorry, what is DBE?
Does it imitate changing clouds in 2022 to 2023 APOD like this?

Click to view full size image 1 or image 2

Unexpected Clouds 2023.pngUnexpected Clouds 2022.png

...

OgetayK wrote: ↑Fri Jan 20, 2023 5:36 pm I'm curious about this red Hα halo around Andromeda. Not to mention previous works, the following comparison has a significant part missing. Maybe the photographers can explain if this is caused by postprocessing (maybe DBE?).
Image 1: https://ibb.co/cX6Lqnz
Image 2: https://ibb.co/6N1c1Ny

AVAO wrote: ↑Tue Jan 17, 2023 8:16 pm

Ann wrote: ↑Tue Jan 17, 2023 6:50 pm

AVAO wrote: ↑Tue Jan 17, 2023 4:56 pm
I see more similarities with NGC 4651 than with IC 2497.



"...The jet-like feature is strikingly coherent and narrow. This feature was previously reported by Vorontsov-Velyaminov (1959) but never interpreted as a stellar tidal stream. Moreover, our deep image shows an additional spectacular crescent shaped shell surrounding the east side of the galaxy that corresponds to the apocenter of the dwarf galaxy. Interestingly, a possible second arc on the western side of the galaxy can also be seen in this image. This structure is less obvious because it is partially hidden by the galaxy's disk. This suggests we are observing a moderately inclined structure projected into the halo of NGC 4651..." https://www.cosmotography.com/images/st ... ights.html

Very good comparison, AVAO!

I found a link to that picture of NGC 4651, and I'm wondering about the insert and the small blue star in brackets. Could that possibly be the core of the small galaxy that was broken up to create that umbrella-like structure of NGC 4651? Although I really wouldn't expect a galactic core to be blue.

And if we are seeing anything even remotely similar in Andromeda, what could the intruding galaxy be? Not, say, M32?

Ann

If I compare the red Hα structures of today's APOD with those of https://apod.nasa.gov/apod/ap221024.html, the red hallo around M31 is completely missing on today's APOD. the red Hα structure of today's APOD therefore seems to be rather detached from M31 in our galaxy. the OIII shell structure, in turn, does not show any interaction with the red Hα structure. For me, M31, the OIII shell structure and the Hα structure are rather far apart. the fine stripe structure of the OIII shell structure indicates that it could also be very close to us. Research will show in the future.

JKLassitterJr wrote: ↑Thu Jan 19, 2023 8:37 pm Question: Why aren't there any light spikes -- that one usually sees in these kinds of photos -- around any of the local stars that are located within our Milky Way galaxy? Surprisingly, the stars in this view are perfect spheres of different sizes, and it is a pleasure to view them this way.

JKLassitterJr wrote: ↑Thu Jan 19, 2023 8:37 pm The APOD for 1-17-23 is absolutely spectacular and looks almost like a painting. I've made it my desktop image.

Question: Why aren't there any light spikes -- that one usually sees in these kinds of photos -- around any of the local stars that are located within our Milky Way galaxy? Surprisingly, the stars in this view are perfect spheres of different sizes, and it is a pleasure to view them this way.

Was an app used to filter out the light spikes around the local stars?

JKLJ

vbasile wrote: ↑Thu Jan 19, 2023 1:30 pm No relationship with a similarly looking feature present in APOD 19th January 23 (just below center right)?

starsurfer wrote: ↑Wed Jan 18, 2023 11:10 pm

pjw wrote: ↑Wed Jan 18, 2023 12:31 am As other have mentioned, the elephant in the room is the uncorrelated H-alpha data when compared to the earlier "deep M31" APOD. If the h-alpha data is real, there should be a good match between the two, but there is not.

As for the OIII no doubt others will be motivated to go deep here to verify these amazing structure.

The OIII structure has already been verified in this image.

pjw wrote: ↑Wed Jan 18, 2023 12:31 am As other have mentioned, the elephant in the room is the uncorrelated H-alpha data when compared to the earlier "deep M31" APOD. If the h-alpha data is real, there should be a good match between the two, but there is not.

As for the OIII no doubt others will be motivated to go deep here to verify these amazing structure.

Ann wrote: ↑Tue Jan 17, 2023 7:13 am The strange OIII cloud right next to Andromeda is slightly similar to the (admittedly quite differently shaped and also starforming) feature known as Hanny's Voorwerp near galaxy IC 2497. Hanny's Voorwerp may have formed as a tidal tail was drawn out of IC 2497 by a passing galaxy, and the tidal tail was later illuminated and ionized (and compressed so that it started forming stars) by a jet from the black hole of IC 2497, when the black hole became a quasar as gas fell into it as a consequence of IC 2497's encounter with another galaxy.

Ann wrote: ↑Tue Jan 17, 2023 6:50 pm

AVAO wrote: ↑Tue Jan 17, 2023 4:56 pm
I see more similarities with NGC 4651 than with IC 2497.



"...The jet-like feature is strikingly coherent and narrow. This feature was previously reported by Vorontsov-Velyaminov (1959) but never interpreted as a stellar tidal stream. Moreover, our deep image shows an additional spectacular crescent shaped shell surrounding the east side of the galaxy that corresponds to the apocenter of the dwarf galaxy. Interestingly, a possible second arc on the western side of the galaxy can also be seen in this image. This structure is less obvious because it is partially hidden by the galaxy's disk. This suggests we are observing a moderately inclined structure projected into the halo of NGC 4651..." https://www.cosmotography.com/images/st ... ights.html

Very good comparison, AVAO!

I found a link to that picture of NGC 4651, and I'm wondering about the insert and the small blue star in brackets. Could that possibly be the core of the small galaxy that was broken up to create that umbrella-like structure of NGC 4651? Although I really wouldn't expect a galactic core to be blue.

And if we are seeing anything even remotely similar in Andromeda, what could the intruding galaxy be? Not, say, M32?

Ann

Chris Peterson wrote: ↑Tue Jan 17, 2023 8:03 pm

johnnydeep wrote: ↑Tue Jan 17, 2023 7:41 pm Why? We know from other measurements that M31 is approaching the Milky Way, so if this green cloudy wisp WAS close to the M-W, M31 would naturally be approaching it as well, right?

As noted in the paper, what's really needed is a spectroscopic measurement of the cloud, so its Doppler shift can be compared to that of M31. If the two are physically associated, it's likely they will share the same common motion.

johnnydeep wrote: ↑Tue Jan 17, 2023 7:41 pm Why? We know from other measurements that M31 is approaching the Milky Way, so if this green cloudy wisp WAS close to the M-W, M31 would naturally be approaching it as well, right?

Ann wrote: ↑Tue Jan 17, 2023 5:09 pm

johnnydeep wrote: ↑Tue Jan 17, 2023 4:48 pm Firstly, this is indeed a triumph of amateur astronomy and an incredible image in itself!

But in contrast to Ann, it sure looks to me like these linearly wispy OIII clouds are much closer to us than to Andromeda. I also don't agree that Andromeda's central blackhole is having (or ever had) any effect on it, even if it is "close" to Andromeda, since close here is still probably at least 50,000 ly away.

On another topic, the paper linked to has this to say:

The vector of M31's proper motion measured by GAIA points roughly to the [O iii] emission arc suggesting a possible interaction of M31 with the Milky Way. But the arc seems much too close to M31 to fit that picture.

But I don't understand what this means. How does M31's motion pointing in the apparent direction of the arc suggest anything about how M31 is interacting with the Milky Way?

Doesn't it at least suggest that the green arc is quite close to M31, and not a feature intrinsic to the Milky Way?

Ann

AVAO wrote: ↑Tue Jan 17, 2023 4:56 pm
I see more similarities with NGC 4651 than with IC 2497.



"...The jet-like feature is strikingly coherent and narrow. This feature was previously reported by Vorontsov-Velyaminov (1959) but never interpreted as a stellar tidal stream. Moreover, our deep image shows an additional spectacular crescent shaped shell surrounding the east side of the galaxy that corresponds to the apocenter of the dwarf galaxy. Interestingly, a possible second arc on the western side of the galaxy can also be seen in this image. This structure is less obvious because it is partially hidden by the galaxy's disk. This suggests we are observing a moderately inclined structure projected into the halo of NGC 4651..." https://www.cosmotography.com/images/st ... ights.html

johnnydeep wrote: ↑Tue Jan 17, 2023 4:48 pm Firstly, this is indeed a triumph of amateur astronomy and an incredible image in itself!

But in contrast to Ann, it sure looks to me like these linearly wispy OIII clouds are much closer to us than to Andromeda. I also don't agree that Andromeda's central blackhole is having (or ever had) any effect on it, even if it is "close" to Andromeda, since close here is still probably at least 50,000 ly away.

On another topic, the paper linked to has this to say:

The vector of M31's proper motion measured by GAIA points roughly to the [O iii] emission arc suggesting a possible interaction of M31 with the Milky Way. But the arc seems much too close to M31 to fit that picture.

But I don't understand what this means. How does M31's motion pointing in the apparent direction of the arc suggest anything about how M31 is interacting with the Milky Way?

Ann wrote: ↑Tue Jan 17, 2023 2:50 pm

AVAO wrote: ↑Tue Jan 17, 2023 11:51 am In view of the "perceived" 2,537,000 photos of the Andromeda galaxy by astrophotographers on the internet, the photo and the discovery of the so-called "STROTTNER-DRECHSLER-SAINTY OBJECT 1" (the large blue structure) is an absolute sensation. It is the culmination of a search by this group for several years for as yet undiscovered nebulae in the Milky Way galaxy, as their astrobin side impressively shows. The collaboration with several university organizations and professional astrophysicists and researchers in this context for verification and in-depth research is also exciting. This shows that amateur astronomy can now represent an absolutely essential addition to the large observatories such as HUBBLE or WEBB, since their focus is mostly on smaller areas of the sky and shorter exposure times.

Congratulations on this success!


https://www.astrobin.com/1d8ivk/#rH

https://www.astrobin.com/1d8ivk/H/rawthumb/qhd/?sync

Thank you for the links, AVAO!

I love this RGB + OIII (no Hα) version of today's APOD. All the OII features become to incredibly obvious. There is also a hint of a jet, emerging not from the core of Andromeda but not too far away from it:


Strottner Drechsler Sainty Object 1 OIII no Hα.png


Note all the little green planetary nebulas along the outer dust lane of Andromeda! Fantastic!

Yes, and do note the tiny little green jet that seems to point at the amazing Strottner-Drechsler-Sainty Object 1! Could that green jet possibly, possibly have something to do with the large green OIII feature?

Ann