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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

14824 results found.

  1. GRB 081028B: Fermi GBM detection
  2. GRB 081021: Fermi GBM detection
  3. GRB081028: UVOT detection of a brightening afterglow
  4. Swift UVOT observations of GRB081028
  5. GRB 081028: GROND Detection of the Optical/NIR Afterglow Candidate
  6. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow (Corrected)
  7. Fermi LAT/GBM short-hard GRB 081024B: Possible TLS Afterglow
  8. GRB 081028: Swift detection of a burst
  9. GRB 081024: No radio detection with the VLA
  10. GRB 081025: Burst detection from Swift-BAT slew data
  11. GRB 081024B: Fermi Gamma-ray Burst Monitor detection
  12. GRB 081024: Swift detection of a burst
  13. GRB 081016A: Swift-XRT refined analysis
  14. GRB 081022: Swift detection of a burst
  15. Swift detection of a possible burst (trigger 332287)
  16. GRB 081017: Swift detection of a burst
  17. GRB 081011: Swift XRT refined analysis
  18. GRB 081016B: Swift-XRT Team refined Analysis
  19. GRB 081016B: Swift detection of a burst
  20. GRB 081016: Swift-XRT candidate afterglow detection
  21. Swift detection of flare on CC Eri
  22. Detection of flare star Algol in Swift-BAT slew data
  23. GRB 081009: Fermi GBM detection
  24. GRB 081012: Fermi GBM detection
  25. GRB 081007 and GRB 081007B: Fermi GBM detection
  26. GRB 081012: Swift/XRT detection
  27. GRB 081012: Swift detection of a burst
  28. GRB081011: UVOT detection of an optical afterglow
  29. GRB 081011: Swift/XRT detection
  30. GRB 081011: Swift detection of a burst
  31. GRB 081007: Radio Detection
  32. GRB 081008: VLT/FORS2 spectroscopy
  33. GRB 081008: Swift detection of a burst with optical afterglow
  34. GRB 081008: ROTSE-III Detection of Optical Counterpart
  35. GRB081006B: Fermi GBM detection
  36. GRB081006: Fermi GBM detection
  37. GRB081007: Swift/UVOT Observations
  38. GRB 081007: Swift detection of a burst with optical afterglow
  39. GRB081003C: GLAST Burst Monitor detection
  40. Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
  41. GRB081003B: Optical limits from Spain
  42. GRB 080928: Fermi GBM detection
  43. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  44. Trigger 330353: Swift detection of a Galactic short soft burst
  45. GRB080928: redshift retraction
  46. GRB 080927: Fermi GBM detection
  47. GRB 080928: GROND DETECTION
  48. GRB 080928: Swift detection of a burst with an optical counterpart
  49. GRB 080925: Fermi GBM Detection
  50. GRB 080920: Fermi GBM detection
  51. Swift detection of a possible GRB (trigger 325707)
  52. GRB 080922: Swift/UVOT Upper Limits
  53. GRB 080913B: Fermi GBM detection
  54. GRB 080919: Swift detection of a short burst
  55. GRB 080916A: Fermi GBM detection
  56. GRB 080916C: GROND Detection of the Optical Afterglow Candidate
  57. GRB 080916C: Swift/XRT detection of possible afterglow
  58. GRB 080916B: Swift UVOT Refined Analysis
  59. GRB 080916C: Fermi LAT observation
  60. GRB 080916C: Fermi GBM Detection
  61. GRB 080916B: Swift-XRT afterglow detection
  62. GRB 080916B: Swift detection of a burst
  63. GRB 080916: REM detection of the NIR afterglow
  64. GRB 080916: Swift detection of a burst with optical afterglow
  65. GRB 080912 : Fermi GBM detection
  66. GRB 080915B: Swift detection of a burst
  67. GRB 080915: Swift-XRT afterglow detection and analysis
  68. GRB 080915: Swift detection of a burst
  69. GRB 080913: GROND observation of a high-z optical/NIR afterglow candidate
  70. GRB 080913: Swift detection of a burst
  71. GRB 080906B: Fermi GBM detection
  72. GRB 080905C: Fermi GBM detection
  73. GRB 080905B: Photometric Redshift for the 2MASS Galaxy
  74. GRB080905A: Swift/UVOT Upper Limits
  75. GRB 080905B: Watcher optical detection
  76. GRB 080904: Fermi Gamma-ray Burst Monitor detection
  77. GRB 080905B: Fermi Gamma-ray Burst Monitor detection
  78. GRB 080905A: Fermi Gamma-ray Burst Monitor detection
  79. GRB 080906: Refined Swift/UVOT Observations
  80. GRB 080906: GROND observations of the optical/NIR afterglow
  81. GRB 080905B: Refined UVOT Analysis
  82. GRB 080905B: VLT redshift
  83. GRB 080906: Swift detection of a burst with optical afterglow
  84. GRB080825C: Fermi-LAT observations
  85. GRB 080905B: Swift detection of a burst with possible optical counterpart
  86. GRB 080905: R & I-band optical observations
  87. GRB 080905: Swift detection of a probably-short burst
  88. GRB 080903: Swift/UVOT Observations
  89. GRB 080903: Swift detection of a burst
  90. Recent VLA non-detection of SGR 0501+4516
  91. GRB 080830: Fermi Gamma-ray Burst Monitor detection
  92. GRB080828: Swift/UVOT Upper Limits
  93. SGR 0501+4516: Detection of possible optical counterpart
  94. SGR 0501+4516: WHT observations of the possible near-infrared counterpart
  95. GRB080825B: Swift/UVOT Upper Limits
  96. GRB 080828: Swift-XRT detection of a possible X-ray afterglow
  97. VLA non-detection of SGR 0501+4516
  98. Radio Detection of SGR 0501+4516: Retraction
  99. Swift trigger 322590: BAT detection of a possible burst
  100. SGR 0501+4516: Decline in Activity

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