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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"

43899 results found.

  1. GRB 261026B: AstroSat CZTI detection
  2. GRB 261024D: Insight-HXMT/HE detection
  3. GRB261026A: Infrared detection with MDM/MIRAGE
  4. GRB 261026A: SVOM/VT optical blue bump
  5. GRB 261026A: SAO RAS optical observations
  6. GRB 261024D: GECAM-B observation
  7. The EP-WXT trigger 01709321750 is likely a flaring star
  8. EP Alert 261026.29: Global MASTER-Net observations report
  9. GRB 261026A: EP-FXT follow-up observation
  10. GRB 261024A: SVOM/GRM observation
  11. GRB 261026A: Upper Limit with 60cm Panzhihua Telescope
  12. EP 261025a: J-band upper limit with MIRAGE
  13. GRB 261026A: OHP/T120 optical imaging
  14. GRB 261024D: Glowbug gamma-ray detection
  15. GRB 261026B: NuSTAR detection of prompt emission
  16. GRB 261024D: NuSTAR detection of prompt emission
  17. GRB 261024C: NuSTAR detection of prompt emission
  18. GRB 261026A: Ondrejov D50 optical limit
  19. GRB 261026A: ULL-ASTRO-MASTER optical detection with LCO 40-cm telescope at Haleakalā Observatory
  20. GRB 261026A: J-band observations by the SYSU 80cm infrared telescope
  21. GRB 261026A: SVOM/VT optical observations
  22. IPN triangulation of GRB 260730B
  23. GRB 261026C: Fermi GBM Final Real-time Localization
  24. GRB 261020A: Insight-HXMT/HE detection
  25. SVOM GRB261026.26: Global MASTER-Net observations report
  26. GRB 261026A: WINTER J-band observations
  27. GRB 261024D: AstroSat CZTI detection of a long burst
  28. GRB 261024C: AstroSat CZTI detection of a long burst
  29. GRB 261019A: GECAM-B observation
  30. GRB 261019A: SVOM/GRM observation
  31. Fermi GRB 261026B: Global MASTER-Net observations report
  32. GRB 261026A: SVOM/VT optical observation from VHF data
  33. GRB 261026A: KAIT optical observations
  34. GRB 261026A: SVOM/COLIBRÍ (FM-GFT) optical observations
  35. GRB 261026B: Fermi GBM Final Real-time Localization
  36. GRB 261024A: NuSTAR detection of prompt emission
  37. GRB 261026A: SVOM detection of a burst
  38. GRB 261025B: Fermi GBM Final Real-time Localization
  39. EP261025a: J-band upper limit with WINTER
  40. EP261023a: J-band upper limit with WINTER
  41. EP 261025a: COLIBRÍ optical upper limit
  42. EP261025a: Einstein Probe detection of a fast X-ray transient
  43. GRB 261025A: Fermi GBM Final Localization Correction
  44. EP261023a: J band upper limit by SYSU 80cm infrared telescope
  45. GRB 261024B: Fermi GBM Final Real-time Localization
  46. EP261015a: VST optical observations
  47. GRB 261024A: BALROG localization (Fermi Trigger 814551785 / GRB 261024683)
  48. GRB 261024A: Fermi GBM Final Real-time Localization
  49. EP261023a: Mondy optical upper limit
  50. EP261015a: MAO/AZT-22 optical observations
  51. EP261015a: VLA non-detection
  52. EP261023a: NOT optical counterpart candidate
  53. EP261023a: Einstein Probe detection of an X-ray transient
  54. GRB 261019A: Insight-HXMT/HE detection
  55. The EP-WXT trigger 01709321472 is likely a flaring star
  56. IceCube-261020A: Upper limits from a search for additional neutrino events in IceCube
  57. NuSTAR 261020, a 830s hard X-ray transient
  58. EP261015a: GSP multiband optical follow-up observations
  59. GRB 261017A: SVOM/GRM observation
  60. GRB 261021A: Fermi GBM Final Real-time Localization
  61. EP261015a: Further optical observations with the 1.3m DFOT
  62. GRB 261020B: AstroSat CZTI detection of a short burst
  63. Fermi-LAT Gamma-ray Observations of IceCube-261020A
  64. EP261015a: AZT-20 Assy-Turgen optical observations
  65. GRB 261020A: Fermi GBM Observation
  66. GRB 261017A: SAO RAS optical upper limit
  67. EP261015a: Wendelstein 43 cm optical observations
  68. GRB 260903A
  69. EP261015a: Follow-up with the 1.3m DFOT
  70. EP261015a: Terskol Zeiss-2000 optical upper limit
  71. EP261007b: Further EP-FXT follow-up observations
  72. GRB 261017A: COLIBRÍ optical upper limit
  73. IceCube-261020A - IceCube observation of a high-energy neutrino candidate track-like event
  74. GRB 261020A: MAXI GSC detection
  75. GRB 261020A: Fermi GBM Final Real-time Localization
  76. EP261015a: COLIBRÍ optical observations of a rebrightening
  77. Konus-Wind detection of GRB 261017A
  78. GRB 261019A: Fermi GBM Final Localization
  79. GRB 261017A: Possible Swift/UVOT Detection
  80. GRB 261017A: Luminance-band upper limit from a 28cm telescope in Chengde
  81. GRB 261017A: Swift-BAT refined analysis
  82. GRB 261017A: a short minimum variability timescale compatible with a compact object merger origin
  83. EP261015b: NOT Optical Observations
  84. GRB 261017A: J band upper limit by the SYSU 80cm infrared telescope
  85. EP261015c: refined analysis of the EP-FXT observation favors a stellar flare interpretation
  86. GRB 261017A : MITSuME Akeno optical upper limits
  87. GRB 261017A: Swift-XRT refined Analysis
  88. GRB 261017A: Nanshan/NEXT optical upper limit
  89. GRB 261017A: Enhanced Swift-XRT position
  90. GRB 261017A: Fermi GBM Observation
  91. GRB261010A: Retraction of Keck/MOSFIRE near-IR source
  92. GRB 261017A: Swift detection of a burst
  93. GRB 261017A: Fermi GBM Final Real-time Localization
  94. EP261015a: Tentative fading of the candidate optical counterpart from the NOT
  95. EP261015b: Refined analysis of EP-FXT observations
  96. EP261015b: J-band upper limit by the SYSU 80cm infrared telescope
  97. EP261015a: refined analysis of EP-FXT observations
  98. EP261015c: J-band upper limit with WINTER
  99. EP261015a: J-band upper limit with WINTER
  100. GRB 261011A: 1.3m DFOT optical upper limit

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