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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"

32721 results found.

  1. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) Detection of an Optical Counterpart Candidate
  2. GRB 260223A: Fermi GBM Observation
  3. GRB 260225A: SVOM/VT optical upper limits
  4. EP260126a: VLA 6 GHz detection
  5. EP260223a: Liverpool Telescope upper limits
  6. GRB 260225A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  7. EP 260225.148: COLIBRÍ Confirmation of flaring star
  8. EP260223a: Xinglong optical upper limit
  9. GRB 260223A: Glowbug gamma-ray detection
  10. EP260213a: Mephisto optical upper limits
  11. EP260223a: EP-FXT follow-up observation
  12. sb26021801: SVOM/VT optical upper limits
  13. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  14. sb26021801: SVOM/C-GFT upper limit
  15. EP260223a: COLIBRÍ optical upper limits
  16. GRB 260223A: SVOM/VT optical observation
  17. GRB 260223A: SVOM/GRM observation
  18. GRB 260223A: COLIBRÍ further optical observations and a brightening
  19. EP260221a: Optical upper limit with Kinder observations
  20. GRB 260223A: COLIBRÍ optical observations
  21. GRB 260223A: DDOTI Optical Candidate
  22. Fermi GRB 260223A: Global MASTER-Net observations report
  23. EP260221a: Liverpool Telescope detection of COLIBRÍ counterpart candidate
  24. EP260221a: COLIBRÍ optical counterpart candidate
  25. EP260221a: Gemini South z-band upper limit
  26. EP260221a: Global MASTER-Net observations report
  27. EP260221a: EP-FXT follow-up observation
  28. Fermi GRB 260221B: Global MASTER-Net observations report
  29. EP260221a: Xinglong optical upper limit
  30. Fermi GRB 260221A: Global MASTER-Net observations report
  31. EP260221a: GOTO optical upper limit
  32. EP260221a: COLIBRÍ optical upper limit
  33. SVOM alert sb26021801: LCO optical upper limit
  34. GRB 260219A: AstroSat CZTI detection
  35. IceCube-260217A: Upper limits from a search for additional neutrino events in IceCube
  36. GRB 260219A: GECAM-B observation of a long burst
  37. Fermi GRB 260219A: Global MASTER-Net observations report
  38. SVOM alert sb26021801: LAST optical upper limit
  39. sb26021801: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  40. Fermi-LAT Gamma-ray Observations of IceCube-260217A
  41. GRB 260214B/EP260214b: SVOM/ECLAIRs detection through targeted search
  42. EP260214b: Mondy optical observations
  43. EP260214b: 1.3m DFOT optical upper limit
  44. EP260210a: Mondy optical upper limits
  45. Konus-Wind detection of GRB 260212A
  46. GRB 260208A: AbAO and Terskol optical upper limits
  47. GRB 260208A: continued Mondy optical observations
  48. IPN triangulation of GRB 260212A
  49. IceCube-260217A - IceCube observation of a high-energy neutrino candidate track-like event
  50. GRB 260213A: GECAM-B observation of a short burst
  51. EP260214b: Liverpool Telescope optical observations
  52. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  53. EP260214b: Optical upper limit with Kinder observations
  54. EP260214a: Optical upper limits with Kinder observations
  55. EP260214b: EP-FXT follow-up observation
  56. EP260214a / GRB 260214A: Fermi-GBM Sub-Threshold Detection
  57. EP260214b: DDOTI Optical Detection
  58. EP260214b: GROWTH-India Telescope optical upper limit
  59. EP260214a: VLT near-infrared observation
  60. EP260214b: SVOM/VT optical observation
  61. EP260214a: NOT optical upper limits
  62. EP260214a: COLIBRÍ optical upper limits
  63. EP260214b: OHP/T120 optical observations
  64. EP260214a: refined analysis of the EP-FXT observation
  65. EP260214b: LCO optical counterpart detection
  66. EP260214b: VLT/X-shooter spectroscopic redshift z = 1.208
  67. GRB 260211A: SVOM/VT optical counterpart
  68. EP260214b: COLIBRÍ optical observations
  69. EP260214a: SVOM/VT optical upper limits
  70. EP260214b: NOT optical counterpart detection
  71. EP260214a: Global MASTER-Net observations report
  72. GRB 260212A: AstroSat CZTI detection
  73. GRB 260212A: Fermi GBM Observation
  74. EP260213a: Liverpool Telescope optical upper limits
  75. EP260213a: Global MASTER-Net observations report
  76. EP260213a: COLIBRÍ optical upper limits
  77. GRB 260212A: GECAM-B observation
  78. EP260213a: Optical upper limits with Kinder observations
  79. EP260213a: SVOM/VT optical upper limit
  80. EP260213a: Mondy R-band optical upper limit
  81. EP260213a: NUTTelA-TAO Early Optical Limits
  82. EP260213a: SVOM/C-GFT upper limit
  83. EP260213a: refined analysis of the EP-FXT observation
  84. GRB 260212A: SVOM/GRM observation of a long burst
  85. GRB 260211A - SVOM/ECLAIRs refined analysis
  86. GRB 260204A: SVOM/ECLAIRs refined analysis
  87. GRB 260211A: EP-FXT follow-up observation
  88. GRB 260211A: SVOM/VT optical observation
  89. GRB 260212A: Glowbug gamma-ray detection
  90. GRB 260211A: GOTO optical upper limit
  91. Fermi GRB 260212A: Global MASTER-Net observations report
  92. GRB 260211A: LAST optical upper limit
  93. GRB 260210A: SVOM/GRM observation
  94. Fermi GBM Sub-Threshold Detection of GRB 260211A
  95. Konus-Wind detection of GRB 260207B
  96. GRB 260128B: SVOM/ECLAIRs refined analysis
  97. GRID detection of GRB 260207B
  98. GRB 260211A: LCO optical upper limits
  99. GRB260131A/B: 3.6m DOT Optical Observations
  100. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits

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