As part of my new article on Gaia DR4 and the inner galaxy, I am writing a quick overview of the history of galactic cartography, dividing it into three periods.

Before Morgan made his famous presentation about spiral structure on 26 December 1951, he and a colleague, J. J. Nassau, published a catalogue of OB stars in January 1951 in this paper. ui.adsabs.harvard.edu/abs/1951ApJ.... The catalog is available in SIMBAD so I thought that I'd try mapping it.

Apparently this is the actual slide that Morgan presented on 26 December 1951 as part of his presentation on spiral structure in the Milky Way. Groups of OB stars are identified in a model Morgan constructed made out of cotton balls.

Just found a new image of Colin Stanley Gum, the Australian astronomer who mapped the southern Milky Way in hydrogen-alpha (discovering the Gum nebula), pioneered radio astronomy in the southern hemisphere and established the current system of galactic coordinates. vwma.org.au/explore/peop...

Does anyone happen to have a photo of the Leiden astronomer Kiem Keng Kwee ? Googling returns nothing.

I've started writing my January article on Gaia DR4 and what it could do to help us map the inner galaxy. The article is called "The Phantom Arm" and I hope to release it during the week of January 5. Image Credit: Stefan Payne-Wardenaar, ESA.

An interesting if biased history of galactic cartography in its first phases in the early 1950s. Morgan and Oort were both amazing astronomers but I think their work would have been replicated soon by other researchers. Grote Reber though ... ui.adsabs.harvard.edu/abs/2008JAHH...

Oh, @galaxymap.bsky.social ? You got cited in another research paper!

Since the last two player tournament was so much fun, we are setting up another one for New Year's Day. #boardgames

After reading through references in more recent papers, it looks like this 1954 paper is the origin of the term "Sagittarius arm" (and possibly "Orion arm" as well). ui.adsabs.harvard.edu/abs/1954BAN....

NGC 3783 Credit: ESA/Hubble & NASA, M. C. Bentz, D. J. V. Rosario

I've finally reached the end of my holiday reading on the history of studies of the inner galaxy, Georgelin and Georgelin's famous 1976 paper "The Spiral Structure of our Galaxy determined from HII regions". ui.adsabs.harvard.edu/abs/1976A%26... This paper locked in a four arm model for decades.

Continuing on into my research into the history of studies of the inner galaxy. I've now reached Burton's work on the Sagittarius arm and discovered that he reached a surprising conclusion. ui.adsabs.harvard.edu/abs/1970IAUS...

As far as I can tell, the first "race track" schematic model of the Milky Way appeared in a Soviet paper in 1964. Here's an English translation done in 1965: ui.adsabs.harvard.edu/abs/1965SvA....

I was just reading a 1963 paper by John B. Whiteoak: "The Spiral Structure of the Southern Milky Way" and reflecting that some things have not changed all that much in more than 60 years. ui.adsabs.harvard.edu/abs/1963PASP...

Settling in for a holiday weekend of board games with my wife. #boardgames

Tonight I decided to try something new. I managed to detect Exoplanet TOI 3714b transiting its host star using my 190MN scope and 2600MM camera. Totally blown away that this is possble from my back yard here in the UK. Transit took 1H 38mins and was about 5% in depth 🤯. #Astrophotography #exoplanet

Worth remembering that Arthur Conan Doyle (yes, the author of the Sherlock Holmes stories) believed that these 1917 fake images of fairies made from paper cutouts were real. Skepticism does not seem to work very well if the image is of something you want to believe is real.

I've created a retro illustrated text adventure game that works on mobile, web or Quest VR headset. Can you retrieve the grixion? horizon.meta.com/world/827765...

✨This NASA/ESA/CSA #Webb Space Telescope image shows the Westerlund 1 cluster, a group of massive stars located in our galaxy which are nearly as bright as a million Suns each. 🌌🎄🧪🔭 🔗 esa.int/ESA_Multimedia/Images/2024/10/The_exotic_stellar_population_of_Westerlund_1

Working on my January article on Gaia DR4 and the inner galaxy and looking at this very interesting image of NGC 2523 processed from Pan-STARRS data by Donald Pelletier.

I'm running a poll on a potential Gaia DR4 Kickstarter over on Mastodon: mastodon.social/@galaxy_map/... #astronomy #cartography #GaiaMission

A little 3I/ATLAS update building on @marshall-eubanks.bsky.social's nice RNAAS from last week. Given its non-grav acceleration and the rate at which it's losing mass, you can work out its size. The answer: a diameter around 1 km, very typical for comets. arxiv.org/abs/2512.18341 🔭 🧪

"What is the point of space travel?" Folks out there have questions. I have answers (or some strong thoughts, at least). 🧪 www.quora.com/What-is-the-...

One of the most amazing people in the history of astronomy. Probably the biggest revolution in astronomy since Galileo built an optical telescope and pointed it at the moon.

Here's a preview of my next Gaia DR4 article scheduled for January. What could Gaia DR4 tell us about the inner galaxy? The first image is figure 8 from Kwee 1954, which may be the first map ever published for the inner galaxy.(ui.adsabs.harvard.edu/abs/1954BAN....) Uses old galactic longitude.

A reason why I suggest holding off on concluding that Betelgeuse really actually for sure has a companion. Many astronomers were convinced that Fomalhaut had a planet. The IAU even gave it a name. But then more evidence arrived.

The Gaia DR4 page has been updated! www.cosmos.esa.int/web/gaia/dr4 This is a one year advance notification of what is expected to be astronomy's biggest Christmas gift ever in 2026!

Seeing these images makes me wish, once again, that we had a public detailed high quality image of the entire sky at visual frequencies. Rubin, like most of the world's best telescopes, is in Chile. Will at least its data be mosaicked together into a publicly available image?

A new article on my site with links to a yet-again revised O-type star map and a summary of stuff I've written about IAU nomenclature for OB associations: kevinjardine.dev/blog/post-15/

Here's a revised O-type star poster with more hot star regions labelled. Partly from the new Quintana OB association map but I've tried to keep the names consistent with the IAU nomenclature. Also some disagreements on Cam OB1 and Cir OB1.

More on OB association nomenclature. In the early 1960s, the Czech astronomer Jaroslav Ruprecht was asked by the IAU to prepare a list of OB associations. He presented the results to the Commission on Star Clusters and Associations in Hamburg, Germany on 26 August, 1964. As part of ...

Same with me. No AOL because not in the US. I only used a waterbed once when staying with a relative but once is enough. So 19 of 20 points. I think that should be "Mix Tape" though - a cassette tape I made of my favourite music and used at parties, arguably entirely in violation of copyright.

Facundo Perez Paolino (Caltech) presents his recent results on a large survey to measure magnetic strengths for hundreds of low-mass pre-main sequence stars, trying improve fidelity of predictions for stellar X-ray, mag fields, stellar winds for young stars, exoplanet stars, (& early Sun) #ExSoCal

Here is a very preliminary reworking of my 1 kpc map using the new Quintana association names. I only used the associations where they seem to be connected with hot star concentrations. They provide names for almost all of the concentrations except for the smaller one around Messier 6.

Following up on the new Quintana paper on OB associations. There are many hot star concentrations in Gaia DR3 that do not have names, and the Quintana paper seems to help with that! Here is my 1 kpc poster overlaid by the new Quintana map. I do notice that the Quintana map is missing Mon OB1.

Very interesting to see this. Cartography is not just about science but about shared usage. Looking forward to seeing if any of the "new" OB associations in this paper get used by other researchers.

A new census of OB associations with Gaia! In this study, we took advantage of my OB stars map to find new OB associations within 1 kpc. The goal was to create a useful reference catalogue for this era, and to trace the star formation and structure of the local Milky Way. #stellarastro #galactic

Love this cluster. I've always called it the Eye of Horus but not an official name.

In January, as part of my series on potential discoveries using Gaia DR4, I'll be writing an article on the history of human attempts to map the inner galaxy. As research for this article, I've been having fun tracing the history of publications on the "Sagittarius arm".

My latest VR project is, paradoxically, a 2D text adventure engine. For more details and information on how you can create your own adventures using a simple JSON file, see this article: kevinjardine.dev/blog/post-14/ #GameDev #IndieDev

I got this encyclopedia of planets in a box of Cracker Jacks back in the 70s.

I love this cautionary tale. Thanks to @chrislintott.bsky.social for the link. A reminder that not everyone who pushes lies is an outright con man. Some are deluded by their own desires. newrepublic.com/article/2028...

Shocked that this still hasn't been resolved.

I'm best known these days for visualizing Gaia Mission data but I've also tried my hand at visualizing HI velocity data. Here, for example, is a slice of HI4PI. I'd love to see more papers about HI4PI.

In case anyone missed this yesterday. The countdown has begun!

I have to give Star Trek writers big credit for their decision to choose a real nearby star as the location for Star Fleet's disastrous battle with the Borg. It's usually the only reason why people have heard of Wolf 359.

Gaia DR4 is expected to be released in December 2026, so today is a good day to start the countdown! Why is Gaia DR4 going to be so exciting? Here are several reasons. kevinjardine.dev/blog/post-13/

It would be amazing if Pico were to release an affordable (less than 1000 euros) 4K per eye VR headset. www.uploadvr.com/pico-2026-he...

A confusing statement. NASA's proposed 2025 budget was 25.4 billion dollars. If this ESA budget was annual, it would be similar. But I think this is for 3 years. ☹️