Gemini daily update

Queue programs observed at Gemini Observatory N/S on 04/20/26 (http://bit.ly/2KhLox3 #astronomy:

A high-resolution image of the reflection nebula IC 2220, also known as the Toby Jug Nebula. The image features a central yellowish-white glow from a red giant star that illuminates the surrounding clouds of gas and dust. These clouds form a distinct, symmetrical butterfly shape, with translucent layers of orange and deep red stretching outward. The texture of the nebula appears wispy and atmospheric, set against a dark background sprinkled with numerous twinkling white stars and several prominent blue stars with sharp diffraction spikes.

This week’s image is of IC 2220! Gemini South’s GMOS captured this brilliant reflection nebula, whose unique shape earned it the nickname Toby Jug Nebula. Check out the 🧵 for another paper using GMOS data!

#Astronomy
📸 credit in thread

Gemini daily update

Queue programs observed at Gemini Observatory N/S on 04/18/26 (http://bit.ly/2KhLox3 #astronomy:

Gemini daily update

Queue programs observed at Gemini Observatory N/S on 04/17/26 (http://bit.ly/2KhLox3 #astronomy:

Gemini daily update

Queue programs observed at Gemini Observatory N/S on 04/16/26 (http://bit.ly/2KhLox3 #astronomy:

Credit:
International Gemini Observatory/NOIRLab/NSF/AURA

Image processing: T.A. Rector (University of Alaska Anchorage/NSF NOIRLab), J. Miller (Gemini Observatory/NSF NOIRLab), M. Rodriguez (Gemini Observatory/NSF NOIRLab), M. Zamani (NSF NOIRLab)

A CCD image of the dense star cluster NGC 1846, overlaid with coordinate axes. Background: A negative-scale astronomical field showing a high density of stars. A tight, spherical concentration of stars is centered near the center. Both the x- and y-axes are labeled in pixels, ranging from 0 to 2,000. A large black square is rotated approximately 45 degrees, framing the central cluster and surrounding field stars. A red circle is centered on the core of the globular cluster, indicating the cluster’s half-light radius.

Stellar Variability at the Main-sequence Turnoff of the Intermediate-age LMC Cluster NGC 1846, by R. Salinas et al. 2018

ui.adsabs.harvard.edu/abs/2018AJ.....

A high-resolution image of the reflection nebula IC 2220, also known as the Toby Jug Nebula. The image features a central yellowish-white glow from a red giant star that illuminates the surrounding clouds of gas and dust. These clouds form a distinct, symmetrical butterfly shape, with translucent layers of orange and deep red stretching outward. The texture of the nebula appears wispy and atmospheric, set against a dark background sprinkled with numerous twinkling white stars and several prominent blue stars with sharp diffraction spikes.

This week’s image is of IC 2220! Gemini South’s GMOS captured this brilliant reflection nebula, whose unique shape earned it the nickname Toby Jug Nebula. Check out the 🧵 for another paper using GMOS data!

#Astronomy
📸 credit in thread

DRAGONS logo

📣 𝗚𝗲𝗺𝗶𝗻𝗶 𝗔𝗻𝗻𝗼𝘂𝗻𝗰𝗲𝗺𝗲𝗻𝘁: DRAGONS v4.2.1 patch for GHOST has been released! This includes updated GHOST look-up table to account for the movement of the slit viewer camera during a recent issue and associated work on the hardware.
@noirlabastro.bsky.social #astronomy

A wide-angle photograph from inside the dome of the Gemini North telescope on Mauna Kea, Hawaii. The massive, blue-painted telescope structure dominates the center, supporting a silver open-truss frame that reaches toward the top of the dome. The dome’s interior is lined with rows of bright vertical lights, and its base features large, open ventilation gates that reveal a panoramic view of a twilight sky with streaks of orange, pink, and deep blue over a darkening horizon. The foreground shows the complex mechanical base and various instruments attached to the underside of the telescope.

Throwback post: The US NGO is hosting a splinter session at the #AAS239 meeting: "Stars and the ISM with GeminiOb’s Fast Turnaround (FT) observations." More details, including the speaker lineup, can be found here: noirlab.edu/science/prog...

#Astronomy

Two-panel plot showing elemental abundances versus atomic number (Z) for the star LAMOST J122216.85−063345.2. Top panel: The y-axis shows log-number abundances, and the x-axis spans atomic numbers 38–92. Red circles with error bars represent measured abundances for elements such as Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Eu, Gd, Dy, Er, Yb, Hf, Os, Ir, Pb, Th, and U. Two comparison curves are overplotted: a gold line for a scaled solar s-process pattern and a teal line for a scaled solar r-process pattern. The observed points generally follow the r-process curve more closely than the s-process curve, especially for heavy neutron-capture elements. Some elements are labeled with small numerical values above/below, indicating relative contributions or scaling factors. Bottom panel: Residuals (difference between observations and model) plotted against atomic number. Vertical bars in gold (s-process) and teal (r-process) show deviations, with the r-process residuals generally closer to zero than the s-process, indicating a better fit. A horizontal line at zero marks perfect agreement.

The NSF @noirlabastro.bsky.social GHOST instrument at Gemini South delivers high-resolution spectra. Astronomers have used it to reveal an actinide-boost, metal-poor halo star with strong r-process signatures, opening new windows on Galactic archaeology. arxiv.org/pdf/2603.29246 #astronomy

DRAGONS logo

📣 𝗚𝗲𝗺𝗶𝗻𝗶 𝗔𝗻𝗻𝗼𝘂𝗻𝗰𝗲𝗺𝗲𝗻𝘁: DRAGONS v4.2.1 patch for GHOST has been released! This includes updated GHOST look-up table to account for the movement of the slit viewer camera during a recent issue and associated work on the hardware.
@noirlabastro.bsky.social #astronomy

A wide-angle photograph from inside the dome of the Gemini North telescope on Mauna Kea, Hawaii. The massive, blue-painted telescope structure dominates the center, supporting a silver open-truss frame that reaches toward the top of the dome. The dome’s interior is lined with rows of bright vertical lights, and its base features large, open ventilation gates that reveal a panoramic view of a twilight sky with streaks of orange, pink, and deep blue over a darkening horizon. The foreground shows the complex mechanical base and various instruments attached to the underside of the telescope.

Throwback post: The US NGO is hosting a splinter session at the #AAS239 meeting: "Stars and the ISM with GeminiOb’s Fast Turnaround (FT) observations." More details, including the speaker lineup, can be found here: noirlab.edu/science/prog...

#Astronomy

Gemini daily update

Queue programs observed at Gemini Observatory N/S on 04/14/26 (http://bit.ly/2KhLox3 #astronomy:

Gemini weekly footprint

Science observations @GeminiObs from 2026-04-09 to 2026-04-15: #astronomy

Two-panel plot showing elemental abundances versus atomic number (Z) for the star LAMOST J122216.85−063345.2. Top panel: The y-axis shows log-number abundances, and the x-axis spans atomic numbers 38–92. Red circles with error bars represent measured abundances for elements such as Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Eu, Gd, Dy, Er, Yb, Hf, Os, Ir, Pb, Th, and U. Two comparison curves are overplotted: a gold line for a scaled solar s-process pattern and a teal line for a scaled solar r-process pattern. The observed points generally follow the r-process curve more closely than the s-process curve, especially for heavy neutron-capture elements. Some elements are labeled with small numerical values above/below, indicating relative contributions or scaling factors. Bottom panel: Residuals (difference between observations and model) plotted against atomic number. Vertical bars in gold (s-process) and teal (r-process) show deviations, with the r-process residuals generally closer to zero than the s-process, indicating a better fit. A horizontal line at zero marks perfect agreement.

The NSF @noirlabastro.bsky.social GHOST instrument at Gemini South delivers high-resolution spectra. Astronomers have used it to reveal an actinide-boost, metal-poor halo star with strong r-process signatures, opening new windows on Galactic archaeology. arxiv.org/pdf/2603.29246 #astronomy

Gemini daily update

Queue programs observed at Gemini Observatory N/S on 04/13/26 (http://bit.ly/2KhLox3 #astronomy:

Long-exposure photograph of a star-filled sky in Mauna Kea, with a bright meteor streaking diagonally across the sky and a soft glow of lights illuminating clouds and distant hills below.

From @noirlabastro.bsky.social: A fireball over Hawai‘i: Captured above Gemini North telescope, a blazing rock streaks through Earth’s atmosphere, lighting up the sky in a fleeting moment. This view comes from the Gemini North Cloudcam. #astronomy
📷: International Gemini Observatory/NOIRLab/NSF/AURA

Gemini daily update

Queue programs observed at Gemini Observatory N/S on 04/12/26 (http://bit.ly/2KhLox3 #astronomy:

Long-exposure photograph of a star-filled sky in Mauna Kea, with a bright meteor streaking diagonally across the sky and a soft glow of lights illuminating clouds and distant hills below.

From @noirlabastro.bsky.social: A fireball over Hawai‘i: Captured above Gemini North telescope, a blazing rock streaks through Earth’s atmosphere, lighting up the sky in a fleeting moment. This view comes from the Gemini North Cloudcam. #astronomy
📷: International Gemini Observatory/NOIRLab/NSF/AURA

Gemini daily update

Queue programs observed at Gemini Observatory N/S on 04/11/26 (http://bit.ly/2KhLox3 #astronomy:

THIS is how you do #Astro alt text!
People that rely on alt text to understand what has been posted, or just curious minds, are not helped *at all* by just stating that the image is 'a galaxy', your gear list, or only the catalog number.
It takes little effort to do better.
🧪 #📷

Gemini daily update

Queue programs observed at Gemini Observatory N/S on 04/10/26 (http://bit.ly/2KhLox3 #astronomy:

A grid of thirteen monochrome images of distant galaxies, arranged in three rows. Each panel displays a different galaxy, primarily appearing as faint, diffuse grey shapes against a lighter grey background. Most of the galaxies show distinct morphological features, including spiral arms, elliptical cores, or irregular edge-on orientations. Each panel is labeled in blue text at the top left with an ID and a redshift value. The redshift values increase progressively from the top-left panel to the bottom-right panel, ranging from z=0.3377 to z=1.1792.

The Evolution of Bulge-dominated Field Galaxies from z ≈ 1 to the Present, by C. Woodrum et al. 2017

ui.adsabs.harvard.edu/abs/2017ApJ....

A deep-space image of NGC 1270. At the center of the frame is a large, glowing elliptical galaxy with a bright core that fades into a soft, hazy golden-white halo. Surrounding it are several prominent spiral galaxies: one at the bottom-left showing distinct, blue-tinted spiral arms, and another to the right with a more distorted, elongated shape. The entire field is densely packed with hundreds of smaller galaxies appearing as tiny smudges of light, interspersed with bright, blue foreground stars characterized by sharp diffraction spikes. The background is a deep, velvety black, making the diverse colors and shapes of the celestial bodies pop with high contrast.

This week’s image is of NGC 1270! Gemini North’s GMOS captured this elliptical galaxy set against the breathtaking backdrop of thousands of other galaxies. Check out the 🧵 for more papers!

#Astronomy
📸 credit in thread

Gemini daily update

Queue programs observed at Gemini Observatory N/S on 04/09/26 (http://bit.ly/2KhLox3 #astronomy:

Credit:
International Gemini Observatory/NOIRLab/NSF/AURA/

Image Processing: J. Miller & M. Rodriguez (International Gemini Observatory/NSF NOIRLab), T.A. Rector (University of Alaska Anchorage/NSF NOIRLab), M. Zamani (NSF NOIRLab)

Acknowledgements: PI: Jisu Kang (Seoul National University)

A grid of thirteen monochrome images of distant galaxies, arranged in three rows. Each panel displays a different galaxy, primarily appearing as faint, diffuse grey shapes against a lighter grey background. Most of the galaxies show distinct morphological features, including spiral arms, elliptical cores, or irregular edge-on orientations. Each panel is labeled in blue text at the top left with an ID and a redshift value. The redshift values increase progressively from the top-left panel to the bottom-right panel, ranging from z=0.3377 to z=1.1792.

The Evolution of Bulge-dominated Field Galaxies from z ≈ 1 to the Present, by C. Woodrum et al. 2017

ui.adsabs.harvard.edu/abs/2017ApJ....

A deep-space image of NGC 1270. At the center of the frame is a large, glowing elliptical galaxy with a bright core that fades into a soft, hazy golden-white halo. Surrounding it are several prominent spiral galaxies: one at the bottom-left showing distinct, blue-tinted spiral arms, and another to the right with a more distorted, elongated shape. The entire field is densely packed with hundreds of smaller galaxies appearing as tiny smudges of light, interspersed with bright, blue foreground stars characterized by sharp diffraction spikes. The background is a deep, velvety black, making the diverse colors and shapes of the celestial bodies pop with high contrast.

This week’s image is of NGC 1270! Gemini North’s GMOS captured this elliptical galaxy set against the breathtaking backdrop of thousands of other galaxies. Check out the 🧵 for more papers!

#Astronomy
📸 credit in thread

A series of three plots arranged in columns, each corresponding to a specific wavelength of light: 849.8 nm, 854.2 nm, and 866.2 nm. These wavelengths represent the Calcium II infrared triplet, often used in stellar and planetary atmosphere research. Top row: 2D heatmaps (transit phase vs. velocity) Each column features a rectangular heatmap showing Fractional Deviation of light. The y-axis is labelled Transit phase ranging from 0.0 to 1.0 and the x-axis is labelled velocity in km/s ranging from approximately -80 to 80. The plots feature a light-colored, vertical ‘streak’ or trail that is visible near 0 km/s in each plot, shifting slightly in velocity as the transit phase progresses. Small white crosses mark specific data points along these trails. Bottom row: 1D line profiles (normalized flux vs. velocity) Directly below each heatmap is a corresponding line graph. In these graphs, the y-axis is labelled Normalized Flux, ranging from 0.7 to 1.0 and the x-axis is labelled velocity in km/s. In each of these plots, a thick black line represents the Avg. Profile. A red line overlaid with a faint orange shaded region represents the MCMC models. Each plot shows a deep ‘W’ shaped absorption profile. There are two primary absorption dips centered around -30 and 30 km/s, with a central peak of higher flux returning toward 1.0 near 0 km/s.

Throwback post: 𝗛-𝗮𝗹𝗽𝗵𝗮 𝗮𝗻𝗱 𝗖𝗮 𝗜𝗜 𝗜𝗻𝗳𝗿𝗮𝗿𝗲𝗱 𝗧𝗿𝗶𝗽𝗹𝗲𝘁 𝗩𝗮𝗿𝗶𝗮𝘁𝗶𝗼𝗻𝘀 𝗗𝘂𝗿𝗶𝗻𝗴 𝗮 𝗧𝗿𝗮𝗻𝘀𝗶𝘁 𝗼𝗳 𝘁𝗵𝗲 𝟮𝟯 𝗠𝘆𝗿 𝗣𝗹𝗮𝗻𝗲𝘁 𝗩𝟭𝟮𝟵𝟴 𝗧𝗮𝘂 𝗰 by A. Feinstein, B. Montet et al. ui.adsabs.harvard.edu/abs/2021AJ..... using GRACES!

#Astronomy