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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"

20357 results found.

  1. GRB 081008: Galaxy associated with z=1.967 absorber
  2. Swift-BAT triggered on the flare star Algol
  3. GRB 080430: optical observations
  4. GRB 081012: Observations from NOT
  5. GRB 081012: Swift/XRT detection
  6. GRB 081012, Swift-BAT refined analysis
  7. GRB081011: UVOT detection of an optical afterglow
  8. GRB 081011: Swift/XRT detection
  9. GRB 081008, SMARTS optical/IR afterglow observations
  10. GRB 081011: Swift detection of a burst
  11. GRB 081007: Radio Detection
  12. GRB081008: Swift/UVOT observations
  13. GRB 081008: Enhanced Swift-XRT position
  14. GRB 081008: Swift detection of a burst with optical afterglow
  15. GRB081007: Swift/UVOT Observations
  16. GRB 081007, SMARTS optical afterglow observations
  17. GRB 081007: Early RAPTOR measurements of optical counterpart
  18. GRB 081007: Enhanced Swift-XRT position
  19. GRB 081007, Faulkes Telescope North optical observations
  20. GRB 081007: REM NIR and optical counterpart
  21. GRB 081007: Swift detection of a burst with optical afterglow
  22. GRB081003C: GLAST Burst Monitor detection
  23. GRB 081003B: TAROT Calern observatory optical observations
  24. AXP 1E 1547.0-5408: Swift/UVOT Upper Limits
  25. GRB 081003A: OSN optical observations
  26. GRB 081001: Further observations from OSN
  27. AXP 1E1547.0-5408: Swift-XRT Team refined analysis
  28. GRB 081003A: Swift-XRT Team position and analysis
  29. SGR 1550-5418 = AXP 1E1547.0-5408 (Trigger 330353)
  30. Trigger 330353: Swift detection of a Galactic short soft burst
  31. GRB 081001: Observations from OSN
  32. GRB 081001: Swift UVOT Observations
  33. GRB 081001: Swift-XRT position
  34. GRB 080928: Watcher observations
  35. GRB 080928: GROND DETECTION
  36. GRB 080928: Enhanced Swift-XRT position
  37. GRB 080928: Swift detection of a burst with an optical counterpart
  38. GRB080922, optical upper limit
  39. Swift trigger 325707: Swift/UVOT Upper Limits
  40. Swift trigger 325707: Swift-XRT upper limit
  41. Swift detection of a possible GRB (trigger 325707)
  42. GRB 080922: Swift/UVOT Upper Limits
  43. Trigger 324561: IGR J08408-4503 detected by Swift
  44. GRB 080916C: Fermi GBM Spectral Analysis
  45. GRB 080919: Swift-XRT refined analysis
  46. GRB 080916C: IRSF/SIRUS NIR Observation
  47. GRB 080916C: GROND Confirmation of the Optical Afterglow
  48. GRB 080916C: GROND Confirmation of the Optical Afterglow
  49. GRB 080919: REM NIR observations
  50. GRB 080919: Swift detection of a short burst
  51. GRB 080915A: GROND upper limits
  52. GRB 080916A: GROND lightcurve
  53. GRB 080916C: Swift UVOT Refined Analysis
  54. GRB 080916C: Swift XRT refined analysis
  55. Konus-Wind observation of GRB 080916C
  56. GRB 080916C: GROND Detection of the Optical Afterglow Candidate
  57. GRB080916A: Spectroscopic redshift
  58. GRB 080916C: Swift/XRT detection of possible afterglow
  59. GRB 080916B: Swift UVOT Refined Analysis
  60. GRB 080916B, Swift-BAT refined analysis
  61. GRB080916A: Refined Swift/UVOT Observations
  62. GRB 080915a, SMARTS optical/IR observations
  63. GRB 080916B: Enhanced Swift-XRT position
  64. GRB 080916C: Fermi LAT observation
  65. GRB 080916A: Swift XRT refined analysis
  66. GRB 080916B: Swift-XRT afterglow detection
  67. GRB 080916A: Enhanced Swift-XRT position
  68. GRB 080916: REM detection of the NIR afterglow
  69. GRB 080916: REM candidate afterglow
  70. GRB 080916: Swift detection of a burst with optical afterglow
  71. GRB 080915: REM NIR early observations
  72. GRB 080915: Swift/UVOT Upper Limits
  73. GRB 080915, Swift-BAT refined analysis
  74. GRB 080913: Swift-XRT refined analysis
  75. GRB080913: Swift/UVOT Upper Limits
  76. GRB 080913: VLT/FORS2 observations
  77. GRB 080913: REM NIR early observations
  78. GRB 080913: Enhanced Swift-XRT position
  79. GRB 080913: GROND observation of a high-z optical/NIR afterglow candidate
  80. GRB 080913: Swift detection of a burst
  81. GRB 080906: Watcher observations
  82. GRB 080906B: Fermi GBM detection
  83. GRB 080905C: Fermi GBM detection
  84. GRB 080905B: Photometric Redshift for the 2MASS Galaxy
  85. Swift trigger 324362 (LS I +61 303 ?)
  86. GRB080905A: Swift/UVOT Upper Limits
  87. GRB 080905B: Watcher optical detection
  88. GRB 080904: Fermi Gamma-ray Burst Monitor detection
  89. GRB 080905A: MITSuME Akeno optical upper limits
  90. GRB 080906: Refined Swift/UVOT Observations
  91. GRB 080906: Swift-XRT Refined Analysis
  92. GRB 080905A: optical afterglow
  93. GRB 080906: GROND observations of the optical/NIR afterglow
  94. GRB 080905B: Refined UVOT Analysis
  95. GRB 080905B: VLT redshift
  96. GRB 080905A: NOT and VLT observations
  97. GRB 080905B: Enhanced Swift-XRT position
  98. GRB 080906: Swift detection of a burst with optical afterglow
  99. GRB080825C: Fermi-LAT observations
  100. GRB 080905B: Swift detection of a burst with possible optical counterpart

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