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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"

41948 results found.

  1. GRB 251013C: J band observations by SYSU 80cm infrared telescope
  2. GRB 251013C: EP-FXT counterpart detection
  3. GRB 251013C: AstroSat CZTI detection
  4. GRB 251011A: Swift/BAT-GUANO arcminute localization of a burst
  5. GRB 251013D: Swift/BAT-GUANO arcminute localization of a burst
  6. GRB 251013C: ALMA detection
  7. GRB 251013C: SVOM/COLIBRÍ (FM-GFT) detection of the optical counterpart
  8. GRB 251013C: DDOTI detection of the optical afterglow
  9. GRB 251013C: SLKT optical afterglow photometry
  10. Swift GRB 251014A: Global MASTER-Net observations report
  11. GRB 251014A: Swift detection of a possibly-short burst
  12. GRB 251014A: Fermi GBM Final Real-time Localization
  13. Fermi trigger No 782044789: Global MASTER-Net observations report
  14. Fermi GRB 251013C: Global MASTER-Net observations report
  15. Fermi GRB 251013B: Global MASTER-Net observations report
  16. Fermi GRB 251013D: Global MASTER-Net observations report
  17. GRB 251013C: Swift-XRT counterpart detection
  18. GRB 251013C: GOTO optical afterglow detection
  19. GRB 251013C: SAO RAS optical observations
  20. GRB 251013C: LCO optical afterglow detection
  21. GRB 251013C: Optical Observations via Virtual Telescope Project, Italy
  22. GRB 251013C: NOT spectroscopic redshift z = 0.572
  23. GRB 251013C: LAST detection of optical counterpart
  24. GRB 251013C: BOOTES-6 early optical detection
  25. GRB 251013D: Fermi GBM Final Real-time Localization
  26. GRB 251013C: SVOM/VT optical observation
  27. GRB 251013C: SVOM detection of a burst
  28. GRB 251013C: Fermi GBM Final Real-time Localization
  29. GRB 251013B: SVOM/GRM observation
  30. GRB 251013A: SVOM/GRM observation
  31. GRB 251003A: Mondy optical upper limit
  32. MASTER OT J011025.98-583210.6 : SVOM/VT optical observation
  33. GRB 251013B: Fermi GBM Final Real-time Localization
  34. Fermi GRB 251013A: Global MASTER-Net observations report
  35. GRB 251013A: Fermi GBM Final Real-time Localization
  36. LIGO/Virgo/KAGRA S251013x: Identification of a GW compact binary merger candidate
  37. GRB 251011B inspection: MASTER orphan GRB detection
  38. GRB 251011A: Insight-HXMT detection
  39. GRB 251011B: Swift/UVOT Upper Limits
  40. Fermi GRB 251011A: Global MASTER-Net observations report
  41. GRB 251012A: Fermi GBM Final Real-time Localization
  42. GRB 251011B: SVOM/GRM observation
  43. GRB 251011B: Swift-XRT refined Analysis
  44. GRB 251011B: Fermi GBM Observation
  45. GRB 251011B : MASTER optical observations
  46. GRB 251011C: Fermi GBM Final Real-time Localization
  47. GRB 251011B: Enhanced Swift-XRT position
  48. GRB 251010A: AstroSat CZTI detection
  49. GRB 251011A: AstroSat CZTI detection
  50. GRB 251009B: SVOM/GRM observation of short GRB
  51. GRB 251011B: Swift detection of a burst
  52. GRB 251011B: Fermi GBM Final Real-time Localization
  53. GRB 251011A: Fermi GBM Final Real-time Localization
  54. GRB 251007B: Swift/UVOT Upper Limits
  55. GRB 251010A: Fermi GBM Final Real-time Localization
  56. GRB251007A: Swift/UVOT Detection
  57. GRB 251009A: GECAM-B detection of a short burst
  58. GRB 251009A: Insight-HXMT detection of a short burst
  59. GRB 251009B (short): Glowbug gamma-ray detection
  60. GRB 251009B: Insight-HXMT detection of a short burst
  61. GRB 251007A: Swift-BAT refined analysis
  62. GRB 251009A: SVOM/GRM observation of short GRB with possible tail emission
  63. GRB 251007A: SVOM/GRM observation
  64. GRB 251007A: Insight-HXMT detection
  65. GRB 251007B - SVOM/ECLAIRs refined analysis
  66. SVOM/sb25101004: SVOM detection of a stellar flare
  67. GRB 251009A: Fermi GBM Final Localization
  68. GRB 250916A: TERI Gamma-ray detection
  69. GRB 250919A: TERI gamma-ray detection
  70. EP251006a: Global MASTER-Net observations report
  71. GRB 251006A: Fermi GBM Observation
  72. GRB 251007A: 1.5m OSN and 2.2m CAHA optical follow-up
  73. GRB 251002A - SVOM/ECLAIRs refined analysis
  74. IceCube alert 141456_888784 retraction
  75. IceCube Alert 251008A: Global MASTER-Net observations report
  76. GRB 251003A: Fermi GBM Observation
  77. GRB 251006B: Fermi GBM Observation
  78. GRB 251007B: COLIBRÍ optical upper limit
  79. GRB 251007A: AstroSat CZTI detection
  80. GRB 251006B/EP251006a: EP-FXT afterglow detection
  81. GRB 250917B: iTelescope T-26 upper limit
  82. EP250911a: Koshka Zeiss-1000 Optical Upper Limit
  83. GRB 251007B: SVOM/VT optical candidate
  84. GRB 251007A: Swift-XRT refined Analysis
  85. GRB 251007A: Enhanced Swift-XRT position
  86. GRB 251007B: Swift-XRT refined Analysis
  87. GRB 251007B: Enhanced Swift-XRT position
  88. GRB 251007A: NOT optical observations
  89. GRB 251007A: AKO Optical Upper Limit
  90. GRB 251006B: Insight-HXMT detection
  91. GRB 251007A: SVOM/C-GFT optical observations
  92. GRB 251005C: PRIME J-band upper limit
  93. Swift GRB 251007B: Global MASTER-Net observations report
  94. GRB 251007A: Glowbug gamma-ray detection
  95. GRB 251007B: SVOM/C-GFT upper limit
  96. Swift GRB 251007A: Global MASTER-Net observations report
  97. GRB 251007B: SVOM detection of a faint burst
  98. GRB 251007B: Swift detection of a burst
  99. GRB 251007A: Swift detection of a burst with an optical counterpart
  100. GRB 250702B/EP250702a: JWST/NIRCam Observations

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