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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"

18467 results found.

  1. GRB 090621B: MTM-500 optical observations
  2. GRB 090709A: Swift UVOT upper limits
  3. GRB 090709A: WHT LIRIS observations
  4. GRB 090709A: P60 Observations
  5. GRB 090709A: NOT optical observations
  6. GRB 090709A: RAPTOR Limits During Gamma-Ray Emission
  7. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  8. GRB 090709A, RIMOTS optical upper limits
  9. GRB 090709A: Enhanced Swift-XRT position
  10. GRB 090709A: Subaru NIR observation
  11. GRB 090709 : planned Suzaku-ToO observation
  12. GRB 090709: Faulkes Telescope North Upper Limits
  13. GRB 090709: PAIRITEL NIR Upper Limits
  14. GRB 090709: Swift detection of a bright burst
  15. GRB 090708: Early RAPTOR Optical Limits
  16. GRB 090708, Swift-BAT refined analysis
  17. GRB 090705: PAIRITEL NIR Observations
  18. GRB 090705: Swift detection of a possible burst
  19. XRF 090702 : RTT150 optical observations
  20. GRB 090529: CrAO optical upper limit
  21. GRB 090529: MTM-500 optical observations
  22. GRB 090703: Fermi GBM detection
  23. GRB 090702: UVOT upper limits
  24. GRB 090313: optical observations
  25. XRF 090702: VLT imaging
  26. XRF 090702: Swift-XRT afterglow position
  27. GRB 090404: Deep optical imaging and possible host association
  28. GRB 090628: Swift/UVOT Upper Limits
  29. GRB080628: SAO RAS optical observations
  30. GRB 090628: GROND upper limits
  31. GRB 090628: Enhanced Swift-XRT position
  32. GRB 090626: IPN localization
  33. GRB 090423: Spitzer observations of the z~8.3 burst
  34. GRB 090625B: Swift/UVOT Upper Limits
  35. GRB 090625B: GROND upper limits
  36. GRB090618: HCT optical observations
  37. GRB 090618: SARA Second Epoch Observations
  38. GRB 090625B: Swift observation of the INTEGRAL GRB 090625B
  39. GRB 090621A: Enhanced Swift-XRT position
  40. GRB 090621B: GRT Optical Observation
  41. GRB 090621A: GRT Optical Observation
  42. GRB 090621B: I-band observations from 1.23m CAHA
  43. GRB 090621B: P60 Observations
  44. GRB 090621B: VLA observations
  45. GRB 090621B: Swift/UVOT Upper Limits
  46. GRB 090621B: RTT150 optical observations
  47. GRB 090621B: Swift detection of a short hard burst
  48. GRB 090621: Swift/UVOT Upper Limits
  49. GRB090618: Spectrum and photometry from 6.0m BTA
  50. GRB 090621: Swift detection of a burst
  51. GRB090618: OAA-OAUV Optical observations
  52. VLA radio detection of GRB 090618
  53. GRB 090618 15GHz radio detection
  54. GRB090618 - Continued optical monitoring and light curve break
  55. GRB 090618: SARA observations
  56. GRB090618: Swift-XRT team refined analysis
  57. GRB090618: Swift/UVOT bright afterglow detection
  58. GRB 090618: SDSS host detection
  59. Swift XRT observations of GRB 090531A
  60. GRB 090618: AGILE observations
  61. GRB 090618: Enhanced Swift-XRT position
  62. GRB 090618 Faulkes Telescope North observations
  63. GRB090618: P60 Optical Afterglow
  64. GRB 090618: Swift detection of a bright burst with optical afterglow
  65. RXTE Discovery of Pulsations from SGR 0418+5729
  66. GRB 090607: Swift/UVOT Upper Limits
  67. GRB 090607: GRAS001 optical observations
  68. GRB 090607: Faulkes Telescope North observations
  69. GRB 090607: Swift detection of a burst
  70. GRB 090530: Further NOT optical observations
  71. GRB 090530: RTT150 Optical Observation
  72. GRB 090529A: RTT150 Optical Observations
  73. GMRT observation of GRB 090424 afterglow
  74. GRB090529: Further NOT optical observations
  75. GRB 090531B: GROND observation
  76. GRB 090530: Early RAPTOR Optical Observations
  77. GRB090529B: ROVOR Upper Limits
  78. GRB 090531A: SARA upper limit
  79. GRB 090531B: Swift/BAT spectral lag results
  80. Corrections to GRB 090531B Swift/UVOT Upper Limits
  81. GRB 090531B, RIMOTS optical upper limits
  82. GRB 090531B: Swift/UVOT Upper Limits
  83. GRB 090529: MITSuME optical observation
  84. GRB 090530: GRT Optical Observation
  85. GRB 090531B: Swift-XRT candidate afterglow position
  86. GRB 090531B: ROTSE-III Optical Limits
  87. GRB 090531: Swift-BAT refined analysis
  88. GRB090530: R-band Observation
  89. GRB 090530: break in light curve
  90. GRB 090531: GROND upper limits
  91. GRB 090531: P60 Observations
  92. GRB 090529: NOT optical observations
  93. GRB 090530: NOT optical observations
  94. GRB090530: Swift XRT refined analysis
  95. GRB090530: Swift/UVOT afterglow detection
  96. GRB 090529: Swift-XRT refined analysis
  97. GRB 090530: Enhanced Swift-XRT position
  98. GRB 090530: GRAS002 refined OA analysis
  99. GRB 090530: GRAS002 optical observations
  100. GRB 090530: PAIRITEL NIR Detections

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