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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"

27251 results found.

  1. GRB261026A: Infrared detection with MDM/MIRAGE
  2. GRB 261026A: SVOM/VT optical blue bump
  3. GRB 261024D: GECAM-B observation
  4. The EP-WXT trigger 01709321750 is likely a flaring star
  5. EP Alert 261026.29: Global MASTER-Net observations report
  6. GRB 261026A: EP-FXT follow-up observation
  7. GRB 261024A: SVOM/GRM observation
  8. GRB 261026A: Upper Limit with 60cm Panzhihua Telescope
  9. EP 261025a: J-band upper limit with MIRAGE
  10. GRB 261026A: OHP/T120 optical imaging
  11. GRB 261026A: Ondrejov D50 optical limit
  12. GRB 261026A: ULL-ASTRO-MASTER optical detection with LCO 40-cm telescope at Haleakalā Observatory
  13. GRB 261026A: J-band observations by the SYSU 80cm infrared telescope
  14. GRB 261026A: SVOM/VT optical observations
  15. GRB 261026C: Fermi GBM Final Real-time Localization
  16. SVOM GRB261026.26: Global MASTER-Net observations report
  17. GRB 261026A: WINTER J-band observations
  18. GRB 261019A: GECAM-B observation
  19. GRB 261019A: SVOM/GRM observation
  20. Fermi GRB 261026B: Global MASTER-Net observations report
  21. GRB 261026A: SVOM/VT optical observation from VHF data
  22. GRB 261026A: KAIT optical observations
  23. GRB 261026A: SVOM/COLIBRÍ (FM-GFT) optical observations
  24. GRB 261026B: Fermi GBM Final Real-time Localization
  25. GRB 261026A: SVOM detection of a burst
  26. GRB 261025B: Fermi GBM Final Real-time Localization
  27. EP261023a: J-band upper limit with WINTER
  28. EP 261025a: COLIBRÍ optical upper limit
  29. EP261025a: Einstein Probe detection of a fast X-ray transient
  30. GRB 261025A: Fermi GBM Final Localization Correction
  31. EP261023a: J band upper limit by SYSU 80cm infrared telescope
  32. GRB 261024B: Fermi GBM Final Real-time Localization
  33. EP261015a: VST optical observations
  34. GRB 261024A: BALROG localization (Fermi Trigger 814551785 / GRB 261024683)
  35. GRB 261024A: Fermi GBM Final Real-time Localization
  36. EP261023a: Mondy optical upper limit
  37. EP261015a: VLA non-detection
  38. EP261023a: NOT optical counterpart candidate
  39. EP261023a: Einstein Probe detection of an X-ray transient
  40. The EP-WXT trigger 01709321472 is likely a flaring star
  41. GRB 261017A: SVOM/GRM observation
  42. GRB 261021A: Fermi GBM Final Real-time Localization
  43. EP261015a: AZT-20 Assy-Turgen optical observations
  44. GRB 261020A: Fermi GBM Observation
  45. EP261015a: Wendelstein 43 cm optical observations
  46. EP261007b: Further EP-FXT follow-up observations
  47. GRB 261017A: COLIBRÍ optical upper limit
  48. GRB 261020A: MAXI GSC detection
  49. GRB 261020A: Fermi GBM Final Real-time Localization
  50. EP261015a: COLIBRÍ optical observations of a rebrightening
  51. GRB 261019A: Fermi GBM Final Localization
  52. GRB 261017A: Possible Swift/UVOT Detection
  53. GRB 261017A: Luminance-band upper limit from a 28cm telescope in Chengde
  54. GRB 261017A: R-band upper limit with the 1.3-m DFOT
  55. GRB 261017A: Swift-BAT refined analysis
  56. EP261015b: NOT Optical Observations
  57. GRB 261017A: J band upper limit by the SYSU 80cm infrared telescope
  58. EP261015c: refined analysis of the EP-FXT observation favors a stellar flare interpretation
  59. GRB 261017A : MITSuME Akeno optical upper limits
  60. GRB 261017A: Swift-XRT refined Analysis
  61. GRB 261017A: Fermi GBM Observation
  62. GRB 261017A: Swift detection of a burst
  63. GRB 261017A: Fermi GBM Final Real-time Localization
  64. EP261015b: Refined analysis of EP-FXT observations
  65. EP261015a: refined analysis of EP-FXT observations
  66. GRB 261011A: 1.3m DFOT optical upper limit
  67. EP261015a: SVOM/VT optical observation
  68. EP241111a and EP250125a: Upper limits from SVOM/GRM Observations
  69. EP261015a: COLIBRÍ optical observations
  70. EP261015c: Einstein Probe detection of a fast X-ray transient
  71. EP261015b: Einstein Probe detection of an X-ray transient
  72. EP261015a: Einstein Probe detection of a fast X-ray transient
  73. EP261015a (WXT 11900947714): Possible optical counterpart from NOT and LCO
  74. The EP-WXT trigger 01709321333 is likely a flaring star
  75. GRB 261010A: LBT tentative near-infrared detection
  76. GRB 261008A: SVOM/GRM observation
  77. GRB 261009A: GECAM-B detection of a burst
  78. GRB 261013A: Fermi GBM Final Real-time Localization
  79. GRB 261011A: Later-epoch J-band upper limit from the SYSU 80 cm infrared telescope
  80. GRID detection of GRB 261010A
  81. GRB 261011A: GECAM-B observation
  82. GRB 261011B: GECAM-B observation
  83. GRB 261010A: J-band upper limit by the SYSU 80cm infrared telescope
  84. GRB 261010A: Swift-XRT refined Analysis
  85. GRB 261011A: Swift-XRT refined Analysis
  86. GRB 261011A: Swift-BAT refined analysis
  87. MAXI GRB261012.23: Global MASTER-Net observations report
  88. GRB 261011A: REM optical/NIR observations
  89. Konus-Wind detection of GRB 261010A
  90. GRB 261011A: SOAR optical afterglow observations at ~17 hours
  91. EP261006a: 10 GHz VLA observations
  92. GRB 261010A: Swift-BAT refined analysis
  93. GRB 261011A : MITSuME Akeno optical afterglow candidate detection
  94. GRB 261011A: Optical followup from Sichuan South Observatory
  95. GRB 261011A: GMG Optical Observation
  96. GRB 261011A: Liverpool Telescope optical observations
  97. GRB 261011A: J-band observations by the SYSU 80cm infrared telescope
  98. GRB 261010A: NOT confirmation of the optical afterglow
  99. GRB 261010A: Fermi GBM Observation
  100. GRB 261011B: Fermi GBM Final Localization

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