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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

32697 results found.

  1. EP260221a: COLIBRÍ optical counterpart candidate
  2. EP260221a: Gemini South z-band upper limit
  3. EP260221a: Global MASTER-Net observations report
  4. EP260221a: EP-FXT follow-up observation
  5. Fermi GRB 260221B: Global MASTER-Net observations report
  6. EP260221a: Xinglong optical upper limit
  7. Fermi GRB 260221A: Global MASTER-Net observations report
  8. EP260221a: GOTO optical upper limit
  9. EP260221a: COLIBRÍ optical upper limit
  10. SVOM alert sb26021801: LCO optical upper limit
  11. GRB 260219A: AstroSat CZTI detection
  12. IceCube-260217A: Upper limits from a search for additional neutrino events in IceCube
  13. GRB 260219A: GECAM-B observation of a long burst
  14. Fermi GRB 260219A: Global MASTER-Net observations report
  15. SVOM alert sb26021801: LAST optical upper limit
  16. sb26021801: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  17. Fermi-LAT Gamma-ray Observations of IceCube-260217A
  18. GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search
  19. EP260214b: Mondy optical observations
  20. EP260214b: 1.3m DFOT optical upper limit
  21. EP260210a: Mondy optical upper limits
  22. Konus-Wind detection of GRB 260212A
  23. GRB 260208A: AbAO and Terskol optical upper limits
  24. GRB 260208A: continued Mondy optical observations
  25. IPN triangulation of GRB 260212A
  26. IceCube-260217A - IceCube observation of a high-energy neutrino candidate track-like event
  27. GRB 260213A: GECAM-B observation of a short burst
  28. EP260214b: Liverpool Telescope optical observations
  29. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  30. EP260214b: Optical upper limit with Kinder observations
  31. EP260214a: Optical upper limits with Kinder observations
  32. EP260214b: EP-FXT follow-up observation
  33. EP260214a / GRB 260214A: Fermi-GBM Sub-Threshold Detection
  34. EP260214b: DDOTI Optical Detection
  35. EP260214b: GROWTH-India Telescope optical upper limit
  36. EP260214a: VLT near-infrared observation
  37. EP260214b: SVOM/VT optical observation
  38. EP260214a: NOT optical upper limits
  39. EP260214a: COLIBRÍ optical upper limits
  40. EP260214b: OHP/T120 optical observations
  41. EP260214a: refined analysis of the EP-FXT observation
  42. EP260214b: LCO optical counterpart detection
  43. EP260214b: VLT/X-shooter spectroscopic redshift z = 1.208
  44. GRB 260211A: SVOM/VT optical counterpart
  45. EP260214b: COLIBRÍ optical observations
  46. EP260214a: SVOM/VT optical upper limits
  47. EP260214b: NOT optical counterpart detection
  48. EP260214a: Global MASTER-Net observations report
  49. GRB 260212A: AstroSat CZTI detection
  50. GRB 260212A: Fermi GBM Observation
  51. EP260213a: Liverpool Telescope optical upper limits
  52. EP260213a: Global MASTER-Net observations report
  53. EP260213a: COLIBRÍ optical upper limits
  54. GRB 260212A: GECAM-B observation
  55. EP260213a: Optical upper limits with Kinder observations
  56. EP260213a: SVOM/VT optical upper limit
  57. EP260213a: Mondy R-band optical upper limit
  58. EP260213a: NUTTelA-TAO Early Optical Limits
  59. EP260213a: SVOM/C-GFT upper limit
  60. EP260213a: refined analysis of the EP-FXT observation
  61. GRB 260212A: SVOM/GRM observation of a long burst
  62. GRB 260211A - SVOM/ECLAIRs refined analysis
  63. GRB 260204A: SVOM/ECLAIRs refined analysis
  64. GRB 260211A: EP-FXT follow-up observation
  65. GRB 260211A: SVOM/VT optical observation
  66. GRB 260212A: Glowbug gamma-ray detection
  67. GRB 260211A: GOTO optical upper limit
  68. Fermi GRB 260212A: Global MASTER-Net observations report
  69. GRB 260211A: LAST optical upper limit
  70. GRB 260210A: SVOM/GRM observation
  71. Fermi GBM Sub-Threshold Detection of GRB 260211A
  72. Konus-Wind detection of GRB 260207B
  73. GRB 260128B: SVOM/ECLAIRs refined analysis
  74. GRID detection of GRB 260207B
  75. GRB 260211A: LCO optical upper limits
  76. GRB260131A/B: 3.6m DOT Optical Observations
  77. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  78. GRB 260208A: Swift UVOT detection
  79. Konus-Wind detection of GRB 260127B
  80. EP260209a: COLIBRÍ optical upper limit
  81. Fermi GRB 260210C: Global MASTER-Net observations report
  82. EP260209a: LCO optical upper limits
  83. EP260210a: Global MASTER-Net observations report
  84. EP260210a: refined analysis of the EP-FXT observation
  85. EP260209a: Global MASTER-Net observations report
  86. GRB 260208A: LCO detection of the optical counterpart
  87. EP260210a: Optical upper limits with Kinder observations
  88. IPN triangulation of GRB 260207B (short/hard with EE)
  89. GRB 260210A: Glowbug gamma-ray detection
  90. EP260210a: SVOM/VT optical upper limit
  91. GRB 260210A: AstroSat CZTI detection
  92. GRB 260208C: AstroSat CZTI detection
  93. EP260210a: COLIBRÍ optical upper limit
  94. EP260210a: SVOM/C-GFT upper limit
  95. GRB 260208B: refined analysis of the EP-FXT observation
  96. GRB 260207B: AstroSat CZTI detection
  97. GRB 260208C: SVOM/GRM observation
  98. GRB 260204A: Swift-XRT afterglow detection
  99. GRB 260208B: AstroSat CZTI detection of a bright long burst
  100. GRB260208A: Liverpool Telescope optical follow-up observations

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