Enrique T Boeneker 🔭
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cosmosidewalk.bsky.social
Enrique T Boeneker 🔭
@cosmosidewalk.bsky.social
430 followers 93 following 110 posts
Amateur astronomer and astrophotographer. Member of AAVSO.
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cosmosidewalk.bsky.social
This team found strong evidence of the existence of a middle age (2-5 Gyr) RR Lyrae star in Trumpler 5 star cluster. This challenges the existing evolutionary models and points out the role of binary associations as early producers of this type of stars.

🧪🔭

arxiv.org/abs/2509.22336
First direct detection of an RR Lyrae star conclusively associated with an intermediate-age cluster
RR Lyrae stars have long been considered unequivocal tracers of old (>10 Gyr) and metal-poor ($\mathrm{[Fe/H]}<-0.5$) stellar populations. First, because these populations are where they are readily f...
arxiv.org
September 29, 2025 at 11:48 AM
Reposted by Enrique T Boeneker 🔭
elisecutts.bsky.social
Cecilia Payne-Gaposchkin ✨ figured out what stars are made of ✨ when she was just 25. 🔭🧪

Her PhD thesis basically established the Harvard astro department — at a time when Harvard didn't officially allow woman students.

I wrote this little profile to mark the 100th anniversary of her thesis:
September 24, 2025 at 9:14 AM
cosmosidewalk.bsky.social
This is, at last, my first picture EVER of the galaxy where we live, the Milky Way.
The place: San Pedro Mártir, Baja California, very close to the National Observatory.

#astronomy #astrophotography
August 26, 2025 at 7:20 PM
cosmosidewalk.bsky.social
In between my science captures, sometimes I shoot a deep sky object of my liking. In this case was the turn of the Double Cluster in Perseus. Ionized hydrogen is present in this region.

#astronomy 🧪🔭
Two populated clusters of stars flank the center of this picture. Most of the stars are young: you can tell because their white and blue hues. Surrounding them, faint red hydrogen clouds pop up here and there.
August 16, 2025 at 11:42 PM
cosmosidewalk.bsky.social
The picture shows the dark molecular cloud close to the bright star Altair in the constellation of Aquila. It is cataloged as LDN 673. Molecular hydrogen, carbon monoxide, and some other molecules form these dark interstellar clouds in which stars are born. 1/3

#Astronomy
August 2, 2025 at 1:09 AM
cosmosidewalk.bsky.social
I like to experiment. This image of the Tulip Nebula (in Cygnus) is a composite of L-Ha-O III-BVR filters. The idea is to show you as much detail of the region where the first confirmed black hole is.
#Astronomy
At the center, the Tulip Nebula stands out from the busy circumstellar environment that surrounds it. Below, you can find a white arc which is a huge bow-shock produced by one of the jets of the first black hole ever confirmed: Cygnus X1.
July 19, 2025 at 10:43 PM
cosmosidewalk.bsky.social
Many of the stars in our Milky Way are part of binary systems. A good percentage of these systems are composed of two stars that orbit each other at a certain distance, but there are other binaries where both of the stars are so close that we can say they almost touch each other. #AstroSci 1/13
Close-up of a two-star system consisting of a main sequence star and a dwarf star. The dwarf star is stealing matter from the main sequence star via an accretion disk that orbits around this star at high speeds. The image is an artist’s impression of such a system.
July 4, 2025 at 5:25 PM
cosmosidewalk.bsky.social
Paracetamol, made out of plastic. This groundbreaking research, published in Nature, reveals a new and unexpected application for PET.
nature.com/articles/d41586-025...
#science
nature.com
June 27, 2025 at 12:52 AM
Reposted by Enrique T Boeneker 🔭
emily.space
Folks in the US: fight harder than you have ever fought for science - and then some. 🔭☄️

Anything less than that will be the beginning of the end of science in America.

See e.g. @planetarysociety.bsky.social's resources for combating NASA cuts:
May 31, 2025 at 12:10 AM
cosmosidewalk.bsky.social
Astronomer’s feng shui…

#astrophotography
May 30, 2025 at 7:48 PM
cosmosidewalk.bsky.social
How do we know that globular star clusters are one of the oldest structures of our universe? The answer is surprisingly fascinating.

Picture number 1 is my latest capture of the largest known globular cluster in the Northern Hemisphere: M13, which I believe contains approximately 500,000 stars.
At the center of the image, you'll find M13, also known as the Great Hercules Globular Cluster. Globular clusters pack thousands of stars in a very "small" volume of a few light years, creating densities that could mean hundreds of stars per cubic parsec in their centers. The challenge as an astrophotographer is to capture the graininess in the appearance of the cluster features.
May 30, 2025 at 12:36 AM
cosmosidewalk.bsky.social
About 1 trillion stars, located 21 million l-y away from us, and featuring a diameter 2.5 times larger than the Milky Way: this is M101, the Pinwheel Galaxy, and I can capture it, with total impunity, with a 103 mm off the shelf telescope. If this is not mind boggling, then what is?
#astronomy
A spiral galaxy with crooked arms that tell past stories of galactic interactions. Billions of stars want to flee for a better place, but the immense gravity of this monster simply don’t let them.
May 21, 2025 at 12:10 AM
cosmosidewalk.bsky.social
Sun.

#astrophotography #astronomy #sun
False color Sun. Originally captured with a narrowband mono filter. There is a large sunspot, much larger than our Earth, to the left of the Sun's center. You can also make up the faculae, which are brighter features close to where the Sun's photosphere has activity.
May 17, 2025 at 5:57 PM
cosmosidewalk.bsky.social
Rising Moon at Pathecito, Mexico.
#landscape
May 9, 2025 at 11:46 PM
cosmosidewalk.bsky.social
Regarding T CrB, the star behaves in the same manner as in recent months. So we have no real clue when its outburst will happen.
These are my most recent photometric observations of this recurrent nova star. (1/2)
#astronomy
The graph shown is called a light curve. It plots the changes in brightness of a star over time. Each point means an observation. The blue points are observations made with a blue photometric filter; the green points represent the observations made with a "visual" filter. By analyzing the shapes of the light curves, we can derive many properties of a particular star or star system.
May 4, 2025 at 4:52 PM
cosmosidewalk.bsky.social
Faint broadband targets are almost a no-no for imagers like me living in a huge city. TBH I never thought I could pull this out: I introduce to y’all part of rho Ophiucci’s nebula!
#astronomy #astrophotography
This blue-ish nebula is part of a bigger complex of colorful nebulae located in the Scorpion constellation. Actually this is very close to the star Antares, a red beacon you can see crossing the Southern skies.
April 30, 2025 at 1:23 PM
Reposted by Enrique T Boeneker 🔭
emily.space
Interested in stellar physics? Orlagh L. Creevey has posted their lecture notes & recorded lecture from a day-long introduction to stellar physics with Gaia!

#astroedu #stellarastro 🔭 🧪
Stellar Physics Across the HR Diagram with Gaia
Gaia Data Release 3 (GDR3) contains a wealth of information to advance our knowledge of stellar physics. In these lecture notes we introduce the data products from GDR3 that can be exploited by the st...
arxiv.org
April 28, 2025 at 6:52 AM
cosmosidewalk.bsky.social
Hey y’all!
Due to the bad weather, I have been revisiting my past pictures, like this one of IC 342. I am slowly improving my processing skills. Had to share this with you.
#astronomy #astrophotography
April 23, 2025 at 2:26 AM
Reposted by Enrique T Boeneker 🔭
astrobites.bsky.social
From Skylar Grayson @skylargrayson.bsky.social : Today’s paper explores a binary quasar system that’s full of mysteries! 🔭✨☄️
astrobites.org/2025/04/04/binary_quasars/
Duel of the Dual: The Mystery of a Quasar Pair
Today's paper explores a binary quasar system that's full of mysteries!
astrobites.org
April 5, 2025 at 3:08 AM
Reposted by Enrique T Boeneker 🔭
stargazerrob.bsky.social
Part of tonight's moon. Enjoyed seeing Janssen (large crater just above center), and Vallis Rheita. Also cool to get a view of Mare Australe (mare in the far south east).

#Moon #Astrodon #astrophotography
Telescopic view of the southeastern region of the 26% illuminated waxing crescent moon, presented north 'up'. The lit region of the moon appears to curve, coming to a point in the lower left of the image. There's a single isolated peak shining beyond the end of the point. A heavily cratered area of the moon. Janssen is near the center of the image and is a large crater containing many other craters. Vallis Rheita is to the upper right of Janssen and is a valley that curves along to the right and down, with quite a few crater impacts. Mare Australe appears as a smoother area right on the very edge of the lower right.
April 2, 2025 at 10:59 PM
Reposted by Enrique T Boeneker 🔭
fraknoi.bsky.social
Nonprofit #OpenStax announced that the free, online book #Astronomy has now been used by 1.3 million students at 2100 colleges, saving them $92 million in textbook costs. Anyone can read it at: bit.ly/astronomytex...
#astroedu #textbooks #freeontheweb #sciencebooks #opensource #openeducation
The free online textbook Astronomy, written by Andrew Fraknoi, David Morrison, and Sidney Wolff, is now the most frequently used intro astronomy textbook in North America.
April 3, 2025 at 6:10 PM
cosmosidewalk.bsky.social
I found out from Wikipedia that this distant object is called Sarah's Galaxy. I find this name more appropriate than the ordinary and vulgar one that people call it.

#astronomy #astrophotography
Seen edge-on, NGC 3628 is known to be a spiral galaxy. However, its profile is odd. Looks thick to me, and its extremes look thicker. I assume this oddness is due to the many interactions it has had with its neighbors that form the famous Leo's Triplet.
March 30, 2025 at 4:45 PM
cosmosidewalk.bsky.social
What if I tell you about a galaxy that has not one but two supermassive black holes? What if I tell you that these SMBH orbit very close to each other, at a distance of about 0.07 l-y? 1/2
#astronomy #astrophysics #astrophotography #space #nightsky #outdoors #galaxy #AGN
M81 is the main galaxy of a group formed by about 34 galaxies. Although it is photographed a lot, I have noticed that in most of the pictures, our galaxy shares credits with M82, a close galaxy it is interacting with. I find, however, proper to take a picture of this galaxy by itself. Did my best to get as much detail as I could and took care to also show an irregular galaxy that turned out to be a satellite of M81: Holmberg IX. You can find this irregular and faint fuzzy at the north of M81. The small pinkish features on the arms of our galaxy are indeed emission nebulae, in which stars are being born.
March 23, 2025 at 3:52 PM
cosmosidewalk.bsky.social
This Thursday, prepare yourself to witness the Lunar Eclipse on a great bilingual live stream...

Find me in YouTube as:
@CosmoSidewalk

#astronomy #lunareclipse #lunareclipse2025
March 11, 2025 at 4:56 PM
cosmosidewalk.bsky.social
I like this galaxy very much. However, I don't know if I like it because of its "grand design" or because it reminds me of The Time Tunnel. Yes, that ancient TV show in which Tony and Douglas were inevitably lost in time. Anyway, this is M51, The Time Tunnel.

#astronomy #astrophotography
In my post, I said the photograph was only of M51, the Whirlpool Galaxy. But that's not true. This galaxy obviously is tearing apart another galaxy, its neighbor: NGC 5195, or M51b for short. The name of M51, the bully, seems appropriate; it is indeed a cosmic maelstrom. I must mention that there are a lot of "cosmic maelstroms" in our universe, so M51 taking all the credit does not seem fair to me. I've added information of the red wavelength known as H-alpha. In this particular wavelength, ionized hydrogen emits a lot of light. Emission nebulae are made mainly of ionized hydrogen, so you can see in this picture many of these kinds of nebulae sparkling with a reddish color, the spiral arms of this majestic thing. How far this thing is, you may ask. Who knows, it might be 15 million l-y or 30 million l-y away, according to the available literature. I take bets. You can find more galaxies, if you're patient enough...
March 7, 2025 at 7:42 PM