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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"

5542 results found.

  1. GRB 130606A: LOAO IZY Observation
  2. GRB 130603B: MASTER-Net early observations and optical sloap limit
  3. GRB 130603A: MITSuME Akeno Optical observation
  4. GRB 130603A: SON optical observations
  5. GRB 130603B: Swift-BAT refined analysis
  6. GRB 130603A: MITSuME Okayama Optical Observation
  7. GRB 130527A: NOT optical counterpart
  8. Swift Trigger 556533 is probably not an astrophysical event
  9. IPN Triangulation of GRB 130521B
  10. GRB 130518A: Fermi GBM detection
  11. GRB 130515A: FORS2 spectroscopy of candidate counterpart
  12. GRB 130511A: SSO 2.3m observation
  13. GRB 130427A: Amateur observations from Sweden
  14. Refined IPN Triangulation of GRB 130502B
  15. GRB 130504C: further Swift-XRT observations
  16. GRB 130504C: Swift-XRT observations
  17. IPN Triangulation of GRB 130504B
  18. GRB 130502B: possible TNG counterpart
  19. GRB 130502B: P60 Observations
  20. GRB 130502B Swift-XRT observations
  21. GRB 130427A: Fermi GBM observation
  22. GRB 130420A: Redshift from 10.4m GTC
  23. Swift Trigger 554135 is probably not a GRB or transient
  24. GRB 130418A: SMARTS optical/IR afterglow observations
  25. GRB 130418A: LOAO Observation
  26. GRB 130418A: CARMA 3mm detection
  27. GRB 130418A: Swift detection of a burst with an optical counterpart
  28. GRB 130408A: SMARTS optical/IR afterglow observations
  29. GRB 130211A: Retraction of afterglow candidate
  30. GRB 130327A: RATIR Optical/NIR afterglow confirmation
  31. GRB 130327A: Weihai optical obsevations
  32. GRB 130327A: ISON-NM optical upper limit
  33. GRB 130327A: RATIR Optical and NIR Observations
  34. GRB130313A: GTC early optical limits
  35. GRB 130305A: PTF P48 optical upper limits
  36. GRB 130313A: NOT optical upper limit
  37. GRB 130313A: Weihai optical upper limit
  38. GRB 130313A: MASTER-Net optical observations
  39. IPN Triangulation of GRB 130307A
  40. Swift XRT observations of GRB 130310A
  41. GRB 130306A: MITSuME Ishigakijima upper limits
  42. IPN triangulation of GRB 130228A
  43. GRB 130305A: Optical Observations
  44. GRB 130307A: Fermi GBM detection
  45. GRB 130306A: MASTER-Net pre-Swift alert observation
  46. GRB 130305A: RATIR Observations
  47. Trigger 549841: Swift detection of SGR1806-20
  48. GRB 130216B: Swift/XRT observations
  49. GRB 130216A: P200 NIR Observations
  50. GRB 130215A: P200 NIR observations
  51. GRB 130215A: GMG optical observation
  52. GRB 130215A: iTelescope T11 observations
  53. GRB 130215A: CARMA 3mm detection
  54. GRB 130211A: GROND detection of the afterglow
  55. GRB 130211A: Swift detection of a burst
  56. GRB 130131A: optical observation in Mondy observatory
  57. GRB 130131A: Swift-BAT refined analysis
  58. GRB 130102B: MAXI/GSC detection
  59. GRB121212A: NOT optical imaging
  60. GRB 121211A: RAPTOR Limits During Gamma-Ray Emitting Interval
  61. GRB 121212A: Swift-BAT refined analysis
  62. GRB 121123A: NOT optical observations
  63. IPN Triangulation of GRB 121118B (long/intense)
  64. GRB 121102A: Swift-XRT refined Analysis
  65. GRB 121031A: Prompt enhanced Swift-XRT position
  66. GRB 121024A: SMARTS optical/IR afterglow observations
  67. GRB 121027A: MASTER early prompt optical limit
  68. GRB 121011A: optical observations
  69. GRB 120921A: Fermi GBM detection of its 1000th GRB
  70. GRB 120909A: Swift detection of a burst
  71. GRB 120907A: NOT optical observations
  72. GRB 120830A: Further Swift Observations
  73. GRB 120811C: optical observations
  74. GRB120804A: Chandra observations and afterglow detection
  75. Swift Trigger 530581: GRB 120811A or a galactic transient
  76. GRB 120803A: optical upper limit
  77. GRB 120804A: MITSuME Okayama Optical upper limits
  78. GRB 120803B: MITSuME Okayama Optical upper limits
  79. GRB 120803A: MITSuME Okayama Optical upper limits
  80. GRB 120803B: MITSuME Akeno Optical upper limits
  81. GRB 120803B: FTN possible afterglow candidate
  82. Swift Trigger 528925 is probably a noise fluctuation
  83. GRB 120724A: optical observation in Maidanak observatory
  84. GRB 120724A: Swift/UVOT Detection of the Optical Afterglow
  85. GRB 120724A: Swift-XRT refined Analysis
  86. GRB 120724A: FTN optical afterglow candidate
  87. GRB 120716A: Swift-XRT detection
  88. GRB 120716A: Optical decay from NOT
  89. GRB 120714B: GROND confirmation of fading afterglow
  90. GRB 120714B: Position Correction and Candidate Optical Afterglow
  91. GRB 120712A: Swift-BAT refined analysis
  92. GRB 120712A: Swift detection of a burst with optical afterglow
  93. Swift detection of GRB 120711B or a new Galactic transient
  94. GRB 120709A: Swift-XRT observations
  95. GRB 120703A: Fermi GBM detection
  96. GRB 120630A: NOT optical source within the XRT error circle
  97. Swift Trigger 525554 is probably not a GRB
  98. GRB 120624B: Fermi GBM detection
  99. Swift trigger 524642 / SwJ1910.2-0546
  100. IPN Triangulation of GRB 120617A (short/intense)

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