South Pole Telescope
@sptelescope.bsky.social
A 10-meter diameter sub-mm wavelength telescope observing the cosmic microwave background from the South Pole, Antarctica.
First LC130 of the season, and second flight of the summer, arrived today at Pole! There should be about 80 new arrivals at Pole this weekend, as the summer season starts in full swing! #Antarctica #southpole @NSF
November 4, 2025 at 4:35 AM
First LC130 of the season, and second flight of the summer, arrived today at Pole! There should be about 80 new arrivals at Pole this weekend, as the summer season starts in full swing! #Antarctica #southpole @NSF
First official flight of the 2025-2026 Austral summer season arrived last Tuesday (Oct-28). Here is a pic from SPT winterover Sim Bash of the arriving crew. Right now we have five SPT'ers in McMurdo hoping to fly to Pole in the next couple days! #Antarctica #southpole
November 3, 2025 at 8:29 PM
First official flight of the 2025-2026 Austral summer season arrived last Tuesday (Oct-28). Here is a pic from SPT winterover Sim Bash of the arriving crew. Right now we have five SPT'ers in McMurdo hoping to fly to Pole in the next couple days! #Antarctica #southpole
New SPT-3G result! "Using SPT-3G we report a 95% limit on ACB of 1.2×10−4, which tightens to 0.53×10−4 when imposing a prior on lensing. These are the tightest constraints on anisotropic birefringence from BB to date"
@vrubinobs.bsky.social @drbriankeating.bsky.social
arxiv.org/abs/2510.07928
@vrubinobs.bsky.social @drbriankeating.bsky.social
arxiv.org/abs/2510.07928
October 16, 2025 at 5:46 PM
New SPT-3G result! "Using SPT-3G we report a 95% limit on ACB of 1.2×10−4, which tightens to 0.53×10−4 when imposing a prior on lensing. These are the tightest constraints on anisotropic birefringence from BB to date"
@vrubinobs.bsky.social @drbriankeating.bsky.social
arxiv.org/abs/2510.07928
@vrubinobs.bsky.social @drbriankeating.bsky.social
arxiv.org/abs/2510.07928
First plane of the 2025-2026 Austral summer season landed at #southpole today! Pic by SPT winterover Sim Bash. This flight is an KBA flight Bassler plane, which is just transiting through @NSF Amundsen-Scott South Pole, on its way to an Italian base. #Antarctica @UChicago
October 13, 2025 at 9:02 PM
First plane of the 2025-2026 Austral summer season landed at #southpole today! Pic by SPT winterover Sim Bash. This flight is an KBA flight Bassler plane, which is just transiting through @NSF Amundsen-Scott South Pole, on its way to an Italian base. #Antarctica @UChicago
Picture of the #sunrise behind SPT and @BICEP_Keck in the Dark Sector from a few weeks ago by SPT winterover Sim Bash #southpole #Antarctica @NSF @doescience
October 10, 2025 at 3:47 AM
Picture of the #sunrise behind SPT and @BICEP_Keck in the Dark Sector from a few weeks ago by SPT winterover Sim Bash #southpole #Antarctica @NSF @doescience
The South Pole Observatory (SPO) collaboration meeting is underway today and tomorrow at UChicago! SPO is a collaboration between the South Pole Telescope and BICEP collaboration!
October 7, 2025 at 9:51 PM
The South Pole Observatory (SPO) collaboration meeting is underway today and tomorrow at UChicago! SPO is a collaboration between the South Pole Telescope and BICEP collaboration!
Our winterovers are trying to find new ways to enjoy the still rising #sunrise. Here is a picture of them from last week trying to find some space for a lawn chair by the #southpole to catch some rays! @NSF
October 6, 2025 at 6:55 PM
Our winterovers are trying to find new ways to enjoy the still rising #sunrise. Here is a picture of them from last week trying to find some space for a lawn chair by the #southpole to catch some rays! @NSF
After being a little cloudy for the first few days after #sunrise, the winterovers are finally starting to see a little bit of #Sun at the #southpole! Pic by winterover Sim Bash! @NSF
September 26, 2025 at 1:50 AM
After being a little cloudy for the first few days after #sunrise, the winterovers are finally starting to see a little bit of #Sun at the #southpole! Pic by winterover Sim Bash! @NSF
This weekend was official #sunrise at the #southpole! Which happens at the autumn equinox. Unfortunately, the weather was very overcast, as you can see from this picture (credit: winterover Sim) during the official sunrise day! #whiteout @NSF @NOAA #Antarctica
September 22, 2025 at 2:43 AM
This weekend was official #sunrise at the #southpole! Which happens at the autumn equinox. Unfortunately, the weather was very overcast, as you can see from this picture (credit: winterover Sim) during the official sunrise day! #whiteout @NSF @NOAA #Antarctica
September 15, 2025 at 11:12 PM
NOAA scientist Ian Crocker on top of the atmospheric monitoring tower at the #southpole (Pic by Kevin Leung).
@noaa.gov
(formerly the US Weather Bureau) have been monitoring weather there since January 1957! #Antarctica
@noaa.gov
(formerly the US Weather Bureau) have been monitoring weather there since January 1957! #Antarctica
September 15, 2025 at 1:10 PM
NOAA scientist Ian Crocker on top of the atmospheric monitoring tower at the #southpole (Pic by Kevin Leung).
@noaa.gov
(formerly the US Weather Bureau) have been monitoring weather there since January 1957! #Antarctica
@noaa.gov
(formerly the US Weather Bureau) have been monitoring weather there since January 1957! #Antarctica
Picture from winterover Sheryl Seagraves. The view from station out to the Dark Sector. Getting much brighter outside about 2-weeks before #sunrise. The red "night" lights from the telescope are becoming less visible against the brightening sky. #Antarctica @NSF
September 5, 2025 at 9:07 PM
Picture from winterover Sheryl Seagraves. The view from station out to the Dark Sector. Getting much brighter outside about 2-weeks before #sunrise. The red "night" lights from the telescope are becoming less visible against the brightening sky. #Antarctica @NSF
Getting closer to #sunrise at the #southpole, with official sunrise still nearly three weeks away. Winterover Sim capturing a picture of the horizon behind the ceremonial South Pole with his rubber duck on top. #Antarctica
September 1, 2025 at 1:10 PM
Getting closer to #sunrise at the #southpole, with official sunrise still nearly three weeks away. Winterover Sim capturing a picture of the horizon behind the ceremonial South Pole with his rubber duck on top. #Antarctica
SPT winterover Sim Bash attempting to play #chess outside at the #southpole during the annual Pole #Olympics, in -30 deg F temps and 30 knot winds. Sim unfortunately reigned after too many pieces blew away. Pic by Zach.
August 25, 2025 at 7:26 PM
SPT winterover Sim Bash attempting to play #chess outside at the #southpole during the annual Pole #Olympics, in -30 deg F temps and 30 knot winds. Sim unfortunately reigned after too many pieces blew away. Pic by Zach.
Nice article describing the devastating impact of the President's Budget on the US Antarctic science program: www.scientificamerican.com/article/u-s-...
U.S. Researchers May Never Probe Deep into Antarctica’s ‘Doomsday Glacier’ Again Without This Ship
The National Science Foundation will stop operating the Nathaniel B. Palmer icebreaker and slash polar science funding by 70 percent, devastating Antarctic research
www.scientificamerican.com
August 19, 2025 at 11:06 PM
Nice article describing the devastating impact of the President's Budget on the US Antarctic science program: www.scientificamerican.com/article/u-s-...
A group of winterovers, including SPT's Karia Dibert, posing in front of the #southpole marker (pic by Kevin Leung). The long exposure helps to see signs of the #sunrise at Pole, but with the stars overhead there will still be some decent night sky viewing. @NSF
August 19, 2025 at 5:18 PM
A group of winterovers, including SPT's Karia Dibert, posing in front of the #southpole marker (pic by Kevin Leung). The long exposure helps to see signs of the #sunrise at Pole, but with the stars overhead there will still be some decent night sky viewing. @NSF
It's still about a month away from official #sunrise at the #southpole, but they are starting to see signs of the Sun on the horizon! Picture by winterover Zeke Mills from the deck on the station! @NSF #southpole
August 18, 2025 at 4:54 AM
It's still about a month away from official #sunrise at the #southpole, but they are starting to see signs of the Sun on the horizon! Picture by winterover Zeke Mills from the deck on the station! @NSF #southpole
Another picture from winterover Zach Tejral of SPT observing a couple weeks ago, with some nice #aurora and the #milkyway just overhead. #Antarctica #southpole @NSF
August 11, 2025 at 6:59 PM
Another picture from winterover Zach Tejral of SPT observing a couple weeks ago, with some nice #aurora and the #milkyway just overhead. #Antarctica #southpole @NSF
Picture from Winter Site Manager Zach Tejral of the Dark Sector Lab (DSL), which hosts the BICEP-3 experiment, and the South Pole Telescope! #ANTARCTICA @NSF @doescience #nsfunded #doefunded
August 9, 2025 at 3:07 AM
Picture from Winter Site Manager Zach Tejral of the Dark Sector Lab (DSL), which hosts the BICEP-3 experiment, and the South Pole Telescope! #ANTARCTICA @NSF @doescience #nsfunded #doefunded
New SPT-3G constraints on early dark energy: "combining with DESI ... we get fEDE=0.071+0.035−0.038 at 68% CL and a weak preference for AEDE over ΛCDM. this shift is a manifestation of the discrepancy present between DESI and CMB experiments in ΛCDM" arxiv.org/abs/2507.23355
August 4, 2025 at 11:02 PM
New SPT-3G constraints on early dark energy: "combining with DESI ... we get fEDE=0.071+0.035−0.038 at 68% CL and a weak preference for AEDE over ΛCDM. this shift is a manifestation of the discrepancy present between DESI and CMB experiments in ΛCDM" arxiv.org/abs/2507.23355
Quick picture by SPT winterover Sim Bash on their way out to the telescope, with the red glow from the station lights in the background, and some nice #aurora overhead! #Antarctica @NSF
July 27, 2025 at 2:36 PM
Quick picture by SPT winterover Sim Bash on their way out to the telescope, with the red glow from the station lights in the background, and some nice #aurora overhead! #Antarctica @NSF
The SPT winterovers recently hosted an open house and tour of the telescope. Since SPT is 1-km from station, many winterovers don't make it out often, so it's nice to have open houses to help learn about the science they are supporting! Pic by Kevin Leung @NSF @doescience
July 7, 2025 at 9:33 PM
The SPT winterovers recently hosted an open house and tour of the telescope. Since SPT is 1-km from station, many winterovers don't make it out often, so it's nice to have open houses to help learn about the science they are supporting! Pic by Kevin Leung @NSF @doescience
It's a couple weeks late, but South Pole recently celebrated mid-winter at the #southpole. Mid-winter is a big milestone for the winterovers, who are spending a year at the South Pole. Attached is the official mid-winter photo, and dinner announcement from this season!
July 7, 2025 at 8:22 AM
It's a couple weeks late, but South Pole recently celebrated mid-winter at the #southpole. Mid-winter is a big milestone for the winterovers, who are spending a year at the South Pole. Attached is the official mid-winter photo, and dinner announcement from this season!
SPT/SPT-3G collaboration meeting taking place this week at
@UChicago! Great to see everyone and having great discussions about all the ongoing science analyses of SPT data! @NSF @doescience #Antarctica
@UChicago! Great to see everyone and having great discussions about all the ongoing science analyses of SPT data! @NSF @doescience #Antarctica
July 1, 2025 at 10:31 PM
SPT/SPT-3G collaboration meeting taking place this week at
@UChicago! Great to see everyone and having great discussions about all the ongoing science analyses of SPT data! @NSF @doescience #Antarctica
@UChicago! Great to see everyone and having great discussions about all the ongoing science analyses of SPT data! @NSF @doescience #Antarctica
Photo by Kevin Leung. SPT winterovers watching #aurora at the "End of the World", the unofficial end of the extent of the South Pole station infrastructure footprint. #southpole @NSF
June 30, 2025 at 7:20 PM
Photo by Kevin Leung. SPT winterovers watching #aurora at the "End of the World", the unofficial end of the extent of the South Pole station infrastructure footprint. #southpole @NSF