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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"

28070 results found.

  1. GRB 081011: Enhanced Swift-XRT position
  2. GRB 081016: Swift-XRT candidate afterglow detection
  3. Swift detection of flare on CC Eri
  4. Detection of flare star Algol in Swift-BAT slew data
  5. GRB 081009: Fermi GBM detection
  6. GRB 081012: GROND upper limits
  7. GRB 081008: Galaxy associated with z=1.967 absorber
  8. Swift-BAT triggered on the flare star Algol
  9. GRB 081012: Fermi GBM detection
  10. GRB 081007 and GRB 081007B: Fermi GBM detection
  11. GRB 081008 optical upper limit
  12. GRB 081012: Observations from NOT
  13. GRB 081012: Swift/UVOT analysis of initial observations
  14. GRB 081012: Swift/XRT detection
  15. GRB 081012: Swift detection of a burst
  16. GRB081011: UVOT detection of an optical afterglow
  17. GRB 081011: Swift/XRT detection
  18. GRB 081008, SMARTS optical/IR afterglow observations
  19. GRB 081011: Swift detection of a burst
  20. GRB 081007: Radio Detection
  21. GRB 081007: Rapid PROMPT Detections
  22. GRB 081008: VLT redshift confirmation
  23. GRB 081008: Swift-XRT Refined Analysis
  24. GRB081008: Swift/UVOT observations
  25. GRB 081008: Enhanced Swift-XRT position
  26. GRB 081008: VLT/FORS2 spectroscopy
  27. GRB 081008: Swift detection of a burst with optical afterglow
  28. GRB 081008: ROTSE-III Detection of Optical Counterpart
  29. GRB081006B: Fermi GBM detection
  30. GRB081006: Fermi GBM detection
  31. GRB081007: Swift/UVOT Observations
  32. GRB 081007, SMARTS optical afterglow observations
  33. GRB 081007: Swift-XRT Team refined analysis
  34. GRB 081007: Enhanced Swift-XRT position
  35. GRB 081007, Faulkes Telescope North optical observations
  36. GRB 081007, SMARTS optical/IR afterglow observations
  37. GRB 081007: Swift detection of a burst with optical afterglow
  38. GRB081003C: GLAST Burst Monitor detection
  39. Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
  40. AXP 1E 1547.0-5408: Swift/UVOT Upper Limits
  41. GRB 081003B: Swift-XRT upper limit
  42. GRB 081003A: OSN optical observations
  43. GRB 081001: Further observations from OSN
  44. AXP 1E1547.0-5408: Swift-XRT Team refined analysis
  45. GRB081003B: Optical limits from Spain
  46. GRB 081003A: Swift-XRT Team position and analysis
  47. GRB 080928: Fermi GBM detection
  48. AXP 1E1547.0-5408 (SGR 1550-5418): Fermi GBM detection
  49. SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
  50. Swift discovery of a new Soft Gamma Repeater SGR 1550-5418
  51. Trigger 330353: Swift detection of a Galactic short soft burst
  52. GRB 081001: Observations from OSN
  53. GRB 081001: Swift UVOT Observations
  54. GRB 081001: Swift-XRT position
  55. GRB080928: redshift retraction
  56. GRB 080928: Watcher observations
  57. GRB 080927: Fermi GBM detection
  58. GRB 080928: VLT redshift
  59. GRB 080928: Swift-XRT refined analysis
  60. GRB 080928: GROND DETECTION
  61. GRB 080928: Enhanced Swift-XRT position
  62. GRB 080928, Swift-BAT initial refined analysis
  63. GRB 080928: Swift detection of a burst with an optical counterpart
  64. GRB 080925: Fermi GBM Detection
  65. GRB 080920: Fermi GBM detection
  66. Swift trigger 325707: Swift-XRT upper limit
  67. Swift detection of a possible GRB (trigger 325707)
  68. GRB 080922: Swift/UVOT Upper Limits
  69. GRB080922: Swift-XRT upper limit
  70. GRB 080913B: Fermi GBM detection
  71. Trigger 324561: IGR J08408-4503 detected by Swift
  72. GRB 080919: Swift/UVOT Refined Analysis
  73. GRB 080919: Swift-XRT refined analysis
  74. GRB 080916C: IRSF/SIRUS NIR Observation
  75. GRB 080916C: GROND Confirmation of the Optical Afterglow
  76. GRB 080916C: GROND Confirmation of the Optical Afterglow
  77. GRB 080919: REM NIR observations
  78. GRB 080919: Swift detection of a short burst
  79. GRB 080915A: GROND upper limits
  80. GRB 080916A: GROND lightcurve
  81. SGR 0501+4516: preliminary results of the Suzaku ToO observation
  82. GRB 080916A: Rapid PROMPT Observations
  83. GRB 080916A: Fermi GBM detection
  84. GRB 080916C: Swift UVOT Refined Analysis
  85. GRB 080916C: Swift XRT refined analysis
  86. GRB 080916B: Swift-XRT refined analysis
  87. GRB 080916C: GROND Detection of the Optical Afterglow Candidate
  88. GRB 080916C: Enhanced XRT position
  89. GRB 080916C: Swift/XRT detection of possible afterglow
  90. GRB 080916B: Swift UVOT Refined Analysis
  91. GRB080916A: Refined Swift/UVOT Observations
  92. GRB 080915a, SMARTS optical/IR observations
  93. GRB 080916B: Enhanced Swift-XRT position
  94. GRB 080916C: Fermi LAT observation
  95. GRB 080916C: Fermi GBM Detection
  96. GRB 080916A: Swift XRT refined analysis
  97. GRB 080916B: Swift-XRT afterglow detection
  98. GRB 080916A: Enhanced Swift-XRT position
  99. GRB 080916B: Swift detection of a burst
  100. GRB 080916: REM detection of the NIR afterglow

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