Optical Astronomy

tahanson43206 · 2022-03-30 14:11:46

SpaceNut, considering the many posts by Palomar about astronomy (on Earth) I was expecting to find at least ONE topic containing the word "astronomy".

There ** was ** none, so now there is.

This topic is offered for members who would like to highlight generic astronomical discoveries or inventions or just progress.

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tahanson43206 · 2022-03-30 14:11:53

This story is about an achievement by Hubble (and the dedicated astronomers who patiently collected the data).

However, I decided to highlight hopes for a confirmation by the James Webb.

https://www.cnn.com/2022/03/30/world/hu … index.html

To ensure that this truly is a single star, rather than two located very close to one another, the research team will use the recently launched James Webb Space Telescope to observe Earendel. Webb could also reveal the temperature and mass of the star.
“With James Webb, we will be able to confirm that Earendel is indeed just one star, and at the same time quantify which type of star it is,” said study coauthor Sune Toft, leader of the Cosmic Dawn Center and professor at the Niels Bohr Institute in Copenhagen, in a statement. “Webb will even allow us to measure its chemical composition. Potentially, Earendel could be the first known example of the Universe’s earliest generation of stars.”
Astronomers want to know more about the star’s composition because it was formed early after the universe began, long before the universe was filled with the heavy elements created by the deaths of massive stars.
Webb could reveal if Earendel is largely made of primordial hydrogen and helium, making it a Population III star – the stars hypothesized to exist shortly after the big bang.
“Earendel existed so long ago that it may not have had all the same raw materials as the stars around us today,” Welch said. “Studying Earendel will be a window into an era of the universe that we are unfamiliar with, but that led to everything we do know. It’s like we’ve been reading a really interesting book, but we started with the second chapter, and now we will have a chance to see how it all got started.”
And the Webb telescope may help astronomers to find even more distant stars than Hubble can find.
“With Webb, we may see stars even farther than Earendel, which would be incredibly exciting,” Welch said. “We’ll go as far back as we can. I would love to see Webb break Earendel’s distance record.”

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tahanson43206 · 2022-04-21 19:45:31

The Daily Mars Business Calendar is supplied with Mars position data by two different web sites.

theskylive.com in particular, shows Mars against a background of stars, galaxies and the occasional visiting object.

Today, Mars is shown near a very large non-planet object, discovered in 2007, and called (for now) 2007 OR10.

If a NewMars reader sees this post and is curious, it is possible to see the representation of OR10 wth respect to Mars, showing as a blue circled dot as compared to Mars, which is shown in Yellow.

225088 Gonggong
Dwarf planet
View all
Gonggong is a dwarf planet, a member of the scattered disc beyond Neptune. It has a highly eccentric and inclined orbit during which it ranges from 34–101 astronomical units from the Sun. As of 2019, its distance from the Sun is 88 AU, and it is... Wikipedia
Orbital period: 554 years
Discovered: July 17, 2007
Diameter: approximately 1,230 km
Mean radius: 615±25 km
People also ask
How many AU is 2007 or10 from the sun?
Which planet is considered as dwarf planet from 2007?
Why is haumea not a planet?
Where is Quaoar? <<< we have a NewMars member who uses this name as a handle. Apparently it is a celestial object
2007 OR10: Largest Unnamed World in the Solar System | NASA
www.nasa.gov › feature › ames › kepler › 2007-or10-largest-unnamed-wo...
May 11, 2016 · The results peg 2007 OR10 as the largest unnamed world in our solar system and the third largest of the current roster of about half a dozen ...
Dwarf Planet 2007 OR10: Big, Dark, and Slow - Sky & Telescope
skyandtelescope.org › astronomy-news › dwarf-planet-2007-or10-big-dark...
May 24, 2016 · New results show that 2007 OR10 is the largest unnamed body in our solar system and the third largest dwarf planet. (Pluto is not shown here.)
The naming of Trans-Neptunian Object (225088) 2007 OR10 ... - Syfy
www.syfy.com › syfy-wire › help-astronomers-name-trans-neptunian-obje...
Apr 9, 2019 · The object (225088) 2007 OR10 is the largest body in our solar system without a proper name. The astronomers who discovered it want the ...
2007 OR10 is Third-Largest Dwarf Planet, Astronomers Say
www.sci-news.com › astronomy › 2007-or10-third-largest-dwarf-planet-03...
May 13, 2016 · (225088) 2007 OR10, nicknamed 'Snow White,' was discovered in July 2007, by a team of astronomers from the California Institute of Technology ...
2007 OR10 Needs a Name! | The Planetary Society
www.planetary.org › Articles
Apr 9, 2019 · We're asking for your help to pick a suitable name for 2007 OR10 to submit to the International Astronomical Union (IAU).
Dwarfy McPlanetface? The icy world known as 2007 OR10 cries out ...
www.geekwire.com › Space
May 12, 2016 · Astronomers say the icy world known as 2007 OR10 is bigger than they thought, adding to the pressure to give the probably dwarf planet a ...
The Largest Unnamed Object in the Solar System Needs a Title ...
www.smithsonianmag.com › smart-news › astronomers-want-your-help-na...
Apr 12, 2019 · A minor planet that lies beyond Neptune's orbit has no name—much like a certain Game of Thrones character, if you will. In 2007, astronomers ...
The Forgotten Dwarf: Meet the Largest Unnamed Object in Our Solar ...
futurism.com › forgotten-dwarf-meet-largest-unnamed-object-solar-system
Case in point, a team of astronomers have learned that the size of an object in the far reaches of the outer Solar System, called 2007 OR10, was significantly ...
When will 2007 OR10 get a name? | Space | EarthSky
earthsky.org › Space
May 16, 2016 · Astronomers have combined data from two space observatories to reveal that an object in the outer solar system – categorized as a dwarf ...
An Astronomical Detective Tale and the Moon of 2007 OR10
www.universetoday.com › astronomical-detective-tale-moon-2007-or10
Jun 21, 2017 · What would the skies from the tiny moon look like? Well, ancient 2007 OR10 must loom large in its sky, though Sol would only shine as a bright - ...

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tahanson43206 · 2022-04-29 20:40:49

A relative sent the link below:

https://www.cnn.com/2022/04/29/world/ex … index.html

The story is about pains taking research, to tease out the presence of huge comets orbiting a star in our neighborhood.

The system is only a few million years old, much younger than ours, so study of this particular system may help increase understanding of how our solar system developed.

(CNN)The nearby Beta Pictoris planetary system, located 63 light-years away from us, has fascinated researchers for decades.
Now, astronomers have found 30 exocomets, or comets located outside of our solar system, orbiting the sunlike Beta Pictoris star, which makes it even more intriguing.
The Beta Pictoris star was discovered nearly 40 years ago. It is surrounded by a debris disk made of gas and dust, which has already birthed two young planets that orbit the star. It offers researchers a rare chance to watch a planetary system that's in the process of forming. While our solar system is 4.5 billion years old, Beta Pictoris is only 20 million years old -- which is young, astronomically speaking.
Scientists were able to detect a few comets grazing by the star as early as 1987, making them the first comets ever observed around a star besides our sun.

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tahanson43206 · 2022-05-23 09:16:11

In the next 24 (Earth) hours, the view of Mars from Earth will cross the transition from Right Ascension 23 hours 59 minutes 59 seconds to RA 00h 00m 00s

Because this orientation is significant to astronomers, I decided to investigate a bit ....

Here is a preliminary snippet provided by Google. If anyone would care to expand upon this post, I'd be interested in seeing a top view of the galaxy showing the direction we are looking from Earth as we view Mars during the transition.

Orbits and the Ecliptic Plane - HyperPhysics
hyperphysics.phy-astr.gsu.edu › hbase › eclip
These points of intersection are called equinoctial points: classically, the vernal point (RA = 00h 00m 00s and longitude = 0¡) and the autumnal point (RA ...

The history of these designations would be of interest. They are purely arbitrary, and some individual human being must have thought they made sense, and then persuaded everyone else to adopt them as standards.

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tahanson43206 · 2022-08-04 17:59:16

A local radio station occasionally interviews a local amateur astronomer. This gent is something of a celebrity here-abouts, because he's been serving as the volunteer head of a group associated with an historically significant observatory. The observatory itself has long since transitioned to doing public outreach programs, and interviews on the local radio and television outlets are part of the effort.

Today's interview happened to mention the close approach (as seen from Earth) of Mars and Uranus.

I checked TheSkyLive, and found that while the two planets are definitely close in an astronomical sense, they are NOT close enough to overlap in the sky views provided by TheSkyLive.

I'd be interested if anyone in the active membership has knowledge of a viewing program that allows the two objects to appear in the same view.

Here are the coordinates as of a few minutes ago, local time:

Uranus RA 03h 04m 22.9s Dec 16 degrees 57 minutes 56.7 seconds
Mars RA 03h 13m 17.7s Dec 16 degrees 13 minutes 52.4 seconds

Update a bit later .... it turns out August 1st was the date of closest apparent approach, so now the planets will be drifting apart.

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tahanson43206 · 2022-08-05 09:10:27

I asked Google to show online sky scapes other than TheSkyLive.

TheSkyLive is the program/service I consult every day for the current position of Mars with respect to the celestial background, as seen from Earth.

However, the view provided by TheSkyLive is at a magnification such that the view is limited, just as it would be when looking through a telescope.

In fact, I suspect the back ground images ** were ** taken by a telescope, because the quality of the background changes throughout the year.

Google came up with several sites, but this one seemed able to do what i'm looking for:

https://stellarium-web.org/

This site showed Uranus above and to the right of Mars.

The moment of closed (apparent) approach was (apparently) August 1st, so I didn't learn about the approach in time.

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tahanson43206 · 2022-08-13 07:05:37

This post is inspired by the number of a galaxy reported to be in the sky (as seen from Earth) just ahead of Mars in today's Calendar report.

The number of that galaxy is in the range of 1,500,000 .... I took a moment to reflect that there must be a Galaxy #1, defined by an ambitious astronomer hundreds of years ago. The arrival of space satellite astronomical instruments has no doubt helped to accelerate the catalog project.

I was curious to know how many galaxies have been catalogued so far, so asked Google:

While NASA previously determined that there were around two trillion galaxies in the universe, new findings say the number is more likely hundreds of billions. Jan 15, 2021

OK ... but how many have been catalogued?

How many galaxies have we Catalogued?
All in all, Hubble reveals an estimated 100 billion galaxies in the universe or so, but this number is likely to increase to about 200 billion as telescope technology in space improves, Livio told Space.com.
Feb 1, 2022

This next snippet gets a bit closer to the mark:

How many galaxies have been discovered?
astronomy.stackexchange.com › questions › how-many-galaxies-have-bee...
the entire Sloan Digital Sky Survey spectroscopic sample and all existing Hubble Space Telescope surveys (around 1.5 million galaxies in total).

The galaxy reported in today's Mars Calendar was well into the 1.5 million number.

The discussion appears to have shown up on Quora.

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tahanson43206 · 2022-08-13 07:13:49

Following up on a modern computer that can pass connection challenges ...

How many galaxies have we cataloged so far? What was the first in this catalog?
✓ Believe it or not, there is a catalog of galaxy catalogs - List of GALAXY-CATALOG Catalogs [ https://heasarc.gsfc.nasa.gov/docs/cgro … W3Browse/…
See more
How many galaxies have we cataloged so far? What was …
https://www.quora.com/How-many-galaxies-have-we...
Feedback
How Many Galaxies Have We Discovered? - Universe Today
https://www.universetoday.com/36610/how … discovered
Aug 03, 2009 · In just one image for example, the Hubble Ultra Deep Field, above, there are about 10,000 galaxies visible. In our own galaxy, There are between 4 billion 100-300 billion stars in …
Estimated Reading Time: 7 mins
New sky map showcases more than 4 million galaxies, …
https://www.space.com/sky-map-showcases … n-galaxies
Feb 26, 2022 · This video still of data shows the most detailed ever view of our radio universe as revealed by LOFAR, which built a map of 4.4 million galaxies. (Image credit: LOFAR/Frits Sweijen)
Galactic Census: Over 300,000 Galaxies Cataloged By …
https://www.ibtimes.com/galactic-census-over...
Published: Sep 24, 2013
Author: Treye Gr…
Estimated Reading Time: 3 mins
Galactic Census: Over 300,000 Galaxies Cataloged By Thousands Of Volunteer Scientists
27 million galaxy morphologies quantified and cataloged …
https://phys.org/news/2021-04-million-galaxy...
Apr 12, 2021 · 27 million galaxy morphologies quantified and cataloged with the help of machine learning

The phys.org citation ** seems ** to imply that the total of cataloged galaxies might exceed 27 million.

However, I'm thrown for a loop by the term "morphologies" ...

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tahanson43206 · 2022-08-13 07:19:47

Follow up in pursuit of the total number of galaxies catalogued ...

From Google again:

Galaxy morphological classification - Wikipedia
en.wikipedia.org › wiki › Galaxy_morphological_classification
Galaxy morphological classification is a system used by astronomers to divide galaxies into groups based on their visual appearance.
Hubble sequence · De Vaucouleurs system · Numerical Hubble stage

OK ,.. but 27 million groups of galaxies implies (to me at least) there must be MORE than 27 million galaxies, or they wouldn't qualify as a "group"

The mystery deepens.

For Mars_B4_Moon or SpaceNut ... if the question sparks your interest, I'm hoping we can find the number of galaxies catalogued to date, although I recognize that number must be increasing.

However, each new discovery ** must ** be compared to the existing catalogs, to avoid duplication.

Update a few minutes later ...

This Wikipedia article contains historical information about naming of celestial objects from ancient times to the present.

https://en.wikipedia.org/wiki/Astronomi … onventions

I came away from a scan of this article with the impression there is probably NOT a single catalog that lists galaxies from 1 to n.

Instead, a variety of naming conventions have been invented over the years, and the modern machine cataloging systems just use numbers.

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tahanson43206 · 2022-11-22 12:24:13

There is an online orrery that appears to be reasonably accurate:

http://theplanetstoday.com

My trusty mechanical orrery ran out of gas in 2019 (per the manufacturer's specifications) and I've kept it going past it's expiration date for the past three years, but today I lost confidence the gears are working properly.

The manufacturer was in France. The product was trademarked in the US, but the trademark has expired.

The online version seems to be working well enough, but it was nice having an offline mechanical descendant of the pre-Christian-Era orrery designs.

We (humans) may never see the mechanical equivalent again, because (I suspect) the market won't be there.

If you (forum reader) open theplantetstoday.com and advance the counter to 09:08:2022, you'll be able to see how the predicted occultation of Mars by Earth's Moon will occur.

Please note that the time/date display is the European format: DD:MM:YYYY

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tahanson43206 · 2022-12-02 08:12:46

The area (on Earth's surface) where I live is subject to cloud cover ... it is rare to have clear skies...

Last night, by chance, the sky was clear, and the impending arrival of Mars and the Moon in an occultation event was clear.

Mars is bright red in the low Eastern sky in the early evening.

There are a number of web sites offering timing information.

One site predicted the occultation will last 31 (Earth) minutes.

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tahanson43206 · 2022-12-07 06:34:35

TheSkyLive.com includes a planetarium feature....

If this url works, it will show the closing in of the Moon on Mars over coming hours.

skymap.png?c=1670414195

As of 7:30 local time, Mars is at RA 04h 58m 21.3s and the Moon is at RA 03h 23m 16s.

The Moon will occlude Mars in coming hours, as seen from Earth.

If the link above does not work, the view may be pulled up by:

theskylive.com/moon-info

Scroll down to: The Moon Position and Finder Charts

Update 2022/12/08 ... it turns out the image above is refreshed when it is painted for a NewMars viewer.

Since the image is tracking the Moon, I'll add a search term to find it easily, if anyone is curious to know where the Moon is.

SearchTerm:Moon view against constellations provided by TheSkyLive.com

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tahanson43206 · 2022-12-08 10:00:27

https://www.newscientist.com/article/mg … orlds-larg

The link above points to an article about a mercury mirror telescope in India.

A smaller such telescope was built and operated for a while in the US, and probably elsewhere.

My expectation is that this design is able to snap a look at a track in the sky determined by the line of sight from the center of the Earth.

What the world’s largest liquid mirror telescope means for astronomy
The International Liquid Mirror Telescope, perched high in the Himalayas, has finally started making observations. If it succeeds, we could one day put a much larger liquid telescope on the moon
This article has been viewed 10900 times in the last 24 hours.

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kbd512 · 2022-12-08 11:09:36

tahanson43206,

Does this mirror require gravity, or is the mirror surface kept frozen using a cryocooler?

Is it reconfigurable / tunable (less concern about surface imperfection)?

What are the limits regarding how big the device can be?

I was thinking of the electrical mechanism in the adaptive optics of the Lockheed-Martin airborne laser, whereby they could "bend" the optics to adjust where the laser beam became coherent.

tahanson43206 · 2022-12-08 14:10:29

For kbd512 ... thank you for your Post #15, with excellent questions and with a forward looking outlook!

For SpaceNut ... if you have a bit of time, (and I understand your time is limited!), there have been attempts to use mercury to make a telescope in the past. I've read about at least one of them, but that was a while ago. It would be fun/interesting if you could find a bit of history about the design.

Bearing in mind that I am offering this initial reply from memory (which is likely blurred) ... A Mercury telescope reflector is designed to operate in a gravitational field and to create a perfect parabola due to rotation of the container.

The quantity of Mercury a builder can assemble would certainly be a limiting factor in how large a reflector might be built. The quality of the engineering of the rotating table is a factor in the quality of the results.

The mirror at the focus has to be as good as possible.

One benefit of this design is that there is no movable scaffolding. The telescope can only look straight up (from the center of the body where it is installed).

An installation on the Moon could be quite large. Again, I expect the supply of Mercury to be the limiting factor.

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tahanson43206 · 2023-01-31 08:08:19

In preparation of the Daily Mars Business calendar update, I am using several resources. Occasionally the limitations of those resources prevent positive identification of objects near the path of Mars, as seen from Earth.

Today i explored the range of offerings for star identification, and discovered massive, almost overwhelming options. I chose one of the many offerings, and sent a contact form request for help.

https://heasarc.gsfc.nasa.gov/cgi-bin/Feedback

Thank you for submitting your feedback!
Your e-mail has been sent.
Subject: Requesting help finding star by coordinates
I am preparing a daily report on the positon of Mars for a forum of the Mars Society. I'm using theskylive.com as my primary resource, and www-mars.imd.jussieu.fr for additional details. I have a TYC star in view but I cannot see the details on theskylive.com because the star is obscured by the page banner. I can obtain the coordinates of the star using the mouse location pointer: RA 04h 32m 05.3s Dec 24 56 14.7
Is there a way to request details about a star if all I have are the coordinates?
Thanks!
If you care to see my work, it is visible at:
newmars.com/forums Topic: Mars Business Calendar
tahanson43206 (Junior moderator)
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tahanson43206 · 2023-01-31 19:02:53

This very helpful reply arrived from NASA High Energy Research Center ...

SearchTerm:NASA procedure to find star in catalog
SearchTerm:Tycho 2 catalog look up star using coordinates

From: Edward J. Sabol <edward.j.sabol@nasa.gov>

> I am preparing a daily report on the positon of Mars for a forum of the
> Mars Society. I'm using theskylive.com as my primary resource, and
> www-mars.imd.jussieu.fr for additional details. I have a TYC star in view
> but I cannot see the details on theskylive.com because the star is obscured
> by the page banner. I can obtain the coordinates of the star using the
> mouse location pointer: RA 04h 32m 05.3s Dec 24 56 14.7 Is there a way to
> request details about a star if all I have are the coordinates?
Hello! Well, you found our documentation for the Tycho-2 catalog. All you
needed to do was click on the link on that web page to "Browse this
table...." ? That link goes here:
https://heasarc.gsfc.nasa.gov/db-perl/W … re+Options
Then, if you scroll down to the input box labeled "Object Name or
Coordinates", and entered "04 32 05.3, 24 56 14.7" there and clicked the
"Start Search" button, you will find that there is only one match:
TYC 1833-138-1
You can also use the SIMBAD service at the CDS to search by coordinates:
https://simbad.cds.unistra.fr/simbad/sim-coo
The following link is the result of that search:
https://simbad.cds.unistra.fr/simbad/si … CoordList=
They agree that TYC 1833-138-1 is likely the star you are referring to. The
SIMBAD service also gives you some alternative names and other details about
the star.
I hope this helps and hasn't come too late. Our apologies for the tardy
response. Best wishes!
Regards,
Ed Sabol
ARK/RPS Software Development and Support Team, Task Leader
High Energy Astrophysics Science Archive Research Center (HEASARC)
Astrophysics Science Division
NASA / Goddard Space Flight Center

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tahanson43206 · 2023-02-01 09:19:48

Update next day:

My first attempt to use the procedure to find a star using coordinates was not successful.

That is not surprising. I used a mouse to get coordinates of a dot on the screen of theskylive.com.

In this case, I could see that the coordinates differed from the coordinates stored for the object, but I wanted to see what happened anyway.

The lookup procedure worked, and the system displayed a map of objects at the coordinates requested, but the results display was empty.

There may be a way to ask for the nearest object to a set of arbitrary coordinates.

Clearly there is more to learn about this process.

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tahanson43206 · 2023-02-02 11:00:02

Update next day ....

It is possible to find stars in the scientific databases created by NASA, ESA and others.

However, the coordinates of the object need to be fairly close to the values recorded in the database, or a match does not occur.

theskylive.com provides labels for objects, showing the accepted coordinates.

However, the labels are not necessarily useful for identifying the specific object to which they refer.

Example:
HIP 21275
Mouse paw over the star shows as:
RA 04h 33m 51.7s
Dec 24 34 14.5

The label reads:
RA RA 04h 33m 51.8s
Dec 24 30 07.7

When the mouse is positioned according to the label, it is far below.

So the RA readings match, but the Declination is way off.

There is a term of art that may be in play .... "epoch"

I'm not clear on the meaning of the term, but I gather that readings taken from Earth for a given object are accurate within the "epoch" active at the time.

Thus, the display shown by theskylive.com may be based upon historical data that does not match.

This is a non-profit organization, run by volunteers, and dependent upon donations to pay the bills.

Given that, it seems to me this web site does a remarkably GOOD job of showing the background sky as Mars proceeds in it's orbit.

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tahanson43206 · 2023-02-16 19:29:04

The post by Mars_B4_Moon includes a link to a study that shows a possible correlation between black holes and dark energy.

https://newmars.com/forums/viewtopic.ph … 49#p206149

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Mars_B4_Moon · 2023-03-24 04:01:38

Will be observed by amateur and professional?

Newly discovered Comet C/2023 A3 might reach naked-eye brightness when it flies past Earth in 2024.
https://twitter.com/SkyandTelescope/sta … 8458244097

tahanson43206 · 2024-05-09 08:55:06

Mars just passed through perhelion...

Mars's most recent perihelion occurred on Wednesday, May 8, 2024 at 4:08 PDT (11:08 UTC). Perihelion is the point in a planet's orbit when it's closest to the sun. Mars's perihelion in 2024 was at a distance of 1.38 AU.

The event was noted in the daily Mars Business Calender.

The distance between Mars and the Sun was observed to be decreasing, until the change passed through zero, and it is now increasing.

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tahanson43206 · 2024-08-12 18:11:56

Mars and Jupiter are approaching minimum separation as seen from Earth.

NewMars members can "see" the approach in TheSkyLive.com.

The planets are not in the same display panel, but they are very close in declination, and may well show up in the same panel in the next couple of days as Mars moves toward the Right Ascension where Jupiter is now.

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tahanson43206 · 2024-08-13 11:06:23

Update ... Mars is scheduled / predicted to show up in the same panel as Jupiter in the next 10 hours.

Update at 18:00 UTC ... Mars is now predicted to be visible in the Jupiter panel in 5 hours.

The prediction path at TheSkyLive.com now shows Mars in the Jupiter panel as green circles with dots in the center.

Update at 19:30 UTC ... Jupiter is now visible in the Mars panel at TheSkyLive.com

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New Mars Forums

Announcement

#1 2022-03-30 14:11:46

Optical Astronomy

#2 2022-03-30 14:11:53

Re: Optical Astronomy

#3 2022-04-21 19:45:31

Re: Optical Astronomy

#4 2022-04-29 20:40:49

Re: Optical Astronomy

#5 2022-05-23 09:16:11

Re: Optical Astronomy

#6 2022-08-04 17:59:16

Re: Optical Astronomy

#7 2022-08-05 09:10:27

Re: Optical Astronomy

#8 2022-08-13 07:05:37

Re: Optical Astronomy

#9 2022-08-13 07:13:49

Re: Optical Astronomy

#10 2022-08-13 07:19:47

Re: Optical Astronomy

#11 2022-11-22 12:24:13

Re: Optical Astronomy

#12 2022-12-02 08:12:46

Re: Optical Astronomy

#13 2022-12-07 06:34:35

Re: Optical Astronomy

#14 2022-12-08 10:00:27

Re: Optical Astronomy

#15 2022-12-08 11:09:36

Re: Optical Astronomy

#16 2022-12-08 14:10:29

Re: Optical Astronomy

#17 2023-01-31 08:08:19

Re: Optical Astronomy

#18 2023-01-31 19:02:53

Re: Optical Astronomy

#19 2023-02-01 09:19:48

Re: Optical Astronomy

#20 2023-02-02 11:00:02

Re: Optical Astronomy

#21 2023-02-16 19:29:04

Re: Optical Astronomy

#22 2023-03-24 04:01:38

Re: Optical Astronomy

#23 2024-05-09 08:55:06

Re: Optical Astronomy

#24 2024-08-12 18:11:56

Re: Optical Astronomy

#25 2024-08-13 11:06:23

Re: Optical Astronomy

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