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"

32489 results found.

  1. EP260221a: COLIBRÍ optical upper limit
  2. SVOM alert sb26021801: LCO optical upper limit
  3. GRB 260219A: AstroSat CZTI detection
  4. IceCube-260217A: Upper limits from a search for additional neutrino events in IceCube
  5. GRB 260219A: GECAM-B observation of a long burst
  6. Fermi GRB 260219A: Global MASTER-Net observations report
  7. SVOM alert sb26021801: LAST optical upper limit
  8. sb26021801: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  9. Fermi-LAT Gamma-ray Observations of IceCube-260217A
  10. GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search
  11. EP260214b: Mondy optical observations
  12. EP260214b: 1.3m DFOT optical upper limit
  13. EP260210a: Mondy optical upper limits
  14. Konus-Wind detection of GRB 260212A
  15. GRB 260208A: AbAO and Terskol optical upper limits
  16. GRB 260208A: continued Mondy optical observations
  17. IPN triangulation of GRB 260212A
  18. IceCube-260217A - IceCube observation of a high-energy neutrino candidate track-like event
  19. GRB 260213A: GECAM-B observation of a short burst
  20. EP260214b: Liverpool Telescope optical observations
  21. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  22. EP260214b: Optical upper limit with Kinder observations
  23. EP260214a: Optical upper limits with Kinder observations
  24. EP260214b: EP-FXT follow-up observation
  25. EP260214a / GRB 260214A: Fermi-GBM Sub-Threshold Detection
  26. EP260214b: DDOTI Optical Detection
  27. EP260214b: GROWTH-India Telescope optical upper limit
  28. EP260214a: VLT near-infrared observation
  29. EP260214b: SVOM/VT optical observation
  30. EP260214a: NOT optical upper limits
  31. EP260214a: COLIBRÍ optical upper limits
  32. EP260214b: OHP/T120 optical observations
  33. EP260214a: refined analysis of the EP-FXT observation
  34. EP260214b: LCO optical counterpart detection
  35. EP260214b: VLT/X-shooter spectroscopic redshift z = 1.208
  36. GRB 260211A: SVOM/VT optical counterpart
  37. EP260214b: COLIBRÍ optical observations
  38. EP260214a: SVOM/VT optical upper limits
  39. EP260214b: NOT optical counterpart detection
  40. EP260214a: Global MASTER-Net observations report
  41. GRB 260212A: AstroSat CZTI detection
  42. GRB 260212A: Fermi GBM Observation
  43. EP260213a: Liverpool Telescope optical upper limits
  44. EP260213a: Global MASTER-Net observations report
  45. EP260213a: COLIBRÍ optical upper limits
  46. GRB 260212A: GECAM-B observation
  47. EP260213a: Optical upper limits with Kinder observations
  48. EP260213a: SVOM/VT optical upper limit
  49. EP260213a: Mondy R-band optical upper limit
  50. EP260213a: NUTTelA-TAO Early Optical Limits
  51. EP260213a: SVOM/C-GFT upper limit
  52. EP260213a: refined analysis of the EP-FXT observation
  53. GRB 260212A: SVOM/GRM observation of a long burst
  54. GRB 260211A - SVOM/ECLAIRs refined analysis
  55. GRB 260204A: SVOM/ECLAIRs refined analysis
  56. GRB 260211A: EP-FXT follow-up observation
  57. GRB 260211A: SVOM/VT optical observation
  58. GRB 260212A: Glowbug gamma-ray detection
  59. GRB 260211A: GOTO optical upper limit
  60. Fermi GRB 260212A: Global MASTER-Net observations report
  61. GRB 260211A: LAST optical upper limit
  62. GRB 260210A: SVOM/GRM observation
  63. Fermi GBM Sub-Threshold Detection of GRB 260211A
  64. Konus-Wind detection of GRB 260207B
  65. GRB 260128B: SVOM/ECLAIRs refined analysis
  66. GRID detection of GRB 260207B
  67. GRB 260211A: LCO optical upper limits
  68. GRB260131A/B: 3.6m DOT Optical Observations
  69. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  70. GRB 260208A: Swift UVOT detection
  71. Konus-Wind detection of GRB 260127B
  72. EP260209a: COLIBRÍ optical upper limit
  73. Fermi GRB 260210C: Global MASTER-Net observations report
  74. EP260209a: LCO optical upper limits
  75. EP260210a: Global MASTER-Net observations report
  76. EP260210a: refined analysis of the EP-FXT observation
  77. EP260209a: Global MASTER-Net observations report
  78. GRB 260208A: LCO detection of the optical counterpart
  79. EP260210a: Optical upper limits with Kinder observations
  80. IPN triangulation of GRB 260207B (short/hard with EE)
  81. GRB 260210A: Glowbug gamma-ray detection
  82. EP260210a: SVOM/VT optical upper limit
  83. GRB 260210A: AstroSat CZTI detection
  84. GRB 260208C: AstroSat CZTI detection
  85. EP260210a: COLIBRÍ optical upper limit
  86. EP260210a: SVOM/C-GFT upper limit
  87. GRB 260208B: refined analysis of the EP-FXT observation
  88. GRB 260207B: AstroSat CZTI detection
  89. GRB 260208C: SVOM/GRM observation
  90. GRB 260204A: Swift-XRT afterglow detection
  91. GRB 260208B: AstroSat CZTI detection of a bright long burst
  92. GRB260208A: Liverpool Telescope optical follow-up observations
  93. GRB 260208A: Glowbug gamma-ray detection
  94. GRB 260208A: NuSTAR detection of prompt emission
  95. GRB 260208A: Fermi GBM Observation
  96. Fermi GRB 260209A: Global MASTER-Net observations report
  97. GRB 260208B: Swift-XRT observations
  98. GRB 260131A/B: continued Mondy optical observations
  99. GRB 260204A: Swift/UVOT Upper Limits
  100. GRB 260208B: COLIBRÍ optical observations

Advanced

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