Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

22056 results found.

  1. GRB 260924A: Upper limits from a neutrino search with IceCube
  2. Fermi GRB 260926C: Global MASTER-Net observations report
  3. GRB260914A: MAO/AZT-22 optical observations
  4. Fermi GRB 260926A: Global MASTER-Net observations report
  5. GRB 260924A: Near-infrared detection with MDM/MIRAGE
  6. GRB 260924A: COLIBRÍ optical observations
  7. GRB 260924A: Second-epoch J-band upper limit from the SYSU 80 cm infrared telescope
  8. EP260924a: J-band upper limit by SYSU 80cm infrared telescope
  9. GRB 260925A: J-band upper limit by SYSU 80cm infrared telescope
  10. Swift Trigger 1513439 is probably not a GRB
  11. GRB 260925A: Swift/UVOT Upper Limits
  12. Konus-Wind detection of GRB 260924A
  13. GRB 260924A: Extreme Isotropic-equivalent Gamma-ray Energy and encouragement for multiwavelength follow-up observations
  14. GRB 260924A: Optical follow-up observations with Kinder
  15. GRB 260924A: Ondrejov D50 optical afterglow detection
  16. EP260924a: J-band upper limit with WINTER
  17. EP260924a: EP-WXT detection of an X-ray transient
  18. GRB 260924A: J-band observations by the SYSU 80 cm infrared telescope
  19. GRB 260924A: Swift/UVOT Detection
  20. GRB 260924A: GROWTH-India Telescope optical observations
  21. Konus-Wind detection of GRB 260922A
  22. GRB 260922A: COLIBRÍ Confirmation of the Optical Counterpart
  23. Konus-Wind detection of GRB 260921A (possible merger-origin)
  24. GRB 260924A: NOT optical counterpart confirmation
  25. GRB 260924A: detection of a bright optical afterglow by the 1.5m OSN telescope
  26. GRB 260922A: CALET Gamma-Ray Burst Monitor detection
  27. Fermi GRB 260923A: Global MASTER-Net observations report
  28. Trigger_21914: Swift ToO observations
  29. EP260806a: e-MERLIN detection at 5 GHz
  30. Fermi-LAT Gamma-ray Observations of IceCube-260919A
  31. Fermi-LAT Gamma-ray Observations of IceCube-260916A
  32. ATCA observations of GRB 260909A
  33. EP260920a: VLT/HAWK-I near-infrared counterpart confirmation
  34. GRB 260922A: J-band upper limit with WINTER
  35. GRB 260922A: Swift/UVOT Upper Limits
  36. Fermi-LAT Gamma-ray Observations of IceCube-260805A
  37. Konus-Wind detection of GRB 260810A
  38. GRB 260918A: SVOM/ECLAIRs refined analysis
  39. GRB 260922A: SVOM/C-GFT optical upper limit
  40. EP Alert 260921.58: Global MASTER-Net observations report
  41. GRB 260917B:: SVOM/ECLAIRs refined analysis
  42. EP260920a: VLT/HAWK-I near-infrared candidate
  43. Swift GRB 260921A: Global MASTER-Net observations report
  44. GRB 260921A: Swift detection of a burst
  45. EP260920b: VLT/X-shooter spectroscopic redshift z = 3.582
  46. EP260920b: LCO observations
  47. EP260920b: refined analysis of the EP-WXT and EP-FXT observations
  48. EP260920b: COLIBRÍ optical observations
  49. EP Alert 260921.01: Global MASTER-Net observations report
  50. EP260920b: Global MASTER-Net observations report
  51. EP Alert 260920.66: Global MASTER-Net observations report
  52. EP260920a: NOT early time optical upper limits
  53. EP260920a: NOT optical upper limits
  54. EP260917a: Global MASTER-Net observations report
  55. EP260920a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  56. IceCube Alert 260919A: Global MASTER-Net observations report
  57. EP Alert 260919.40: Global MASTER-Net observations report
  58. GRB 260915A: VLT optical and near-infrared upper limits
  59. EP260917a: refined analysis of the EP-FXT observations
  60. EP260806a: Yamaguchi Interferometer radio detections
  61. GRB 260918A: SVOM/C-GFT optical upper limits
  62. EP Alert 260918.62: Global MASTER-Net observations report
  63. EP Alert 260918.24: Global MASTER-Net observations report
  64. SVOM GRB260918.16: Global MASTER-Net observations report
  65. EP260917b: EP-WXT detection of an X-ray transient
  66. EP260917A: J-band upper limit with WINTER
  67. EP Alert 260917.32: Global MASTER-Net observations report
  68. GRB 260915A: Swift-XRT afterglow detection
  69. GRB 260918A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  70. GRB 260918A: SVOM detection of a burst
  71. GRB 260915A: SVOM/ECLAIRs refined analysis
  72. GRB 260917B: WINTER J-band observations
  73. GRB 260917B: SVOM/VT optical observations
  74. SVOM GRB260917.16: Global MASTER-Net observations report
  75. GRB 260917B: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  76. Fermi trigger No 811304653: Global MASTER-Net observations report
  77. GRB 260915A: J-band upper limit with WINTER
  78. Fermi trigger No 811264269: Global MASTER-Net observations report
  79. GRB 260909A: NOEMA detection
  80. GRB 260914A: Mondy and TShAO optical observations
  81. GRB 260914A: SVOM/ECLAIRs refined analysis
  82. GRB 260909A: Swift-XRT observations
  83. MAXI GRB260916.37: Global MASTER-Net observations report
  84. GRB 260915A: Swift ToO observations
  85. GRB 260915A: J-band upper limit by SYSU 80cm infrared telescope
  86. GRB 260915A: SVOM/C-GFT optical upper limits
  87. GRB 260915A: REM optical/NIR observations
  88. GRB 260914A: REM optical/NIR observations
  89. GRB 260914A: VLT/X-shooter observations and redshift confirmation
  90. GRB 260915A: SVOM/VT optical upper limits
  91. GRB 260914A: VLT/X-shooter spectroscopic redshift z = 0.778
  92. GRB 260915A: NOT optical upper limit
  93. SVOM GRB260915.05: Global MASTER-Net observations report
  94. GRB 260915A: SVOM/VT optical upper limits from VHF data
  95. EP Alert 260914.53: Global MASTER-Net observations report
  96. GRB 260914A: SVOM/C-GFT optical observations
  97. GRB 260914A: SVOM/VT optical counterpart confirmation
  98. GRB 260914A: SVOM/VT optical observation from VHF data
  99. GRB 260914A: SVOM/COLIBRÍ (FM-GFT) possible optical counterpart candidate
  100. SVOM GRB260914.47: Global MASTER-Net observations report

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov