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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"

32511 results found.

  1. GRB090618: HCT optical observations
  2. GRB 090618: SARA Second Epoch Observations
  3. GRB 090625B: Faulkes Telescope South observations
  4. GRB 090618: Correction to GCN 9568
  5. GRB 090617: Suzaku WAM observation of the prompt emission
  6. GRB 090621B: GRT Optical Observation
  7. GRB 090621A: GRT Optical Observation
  8. PAIRITEL observations of GRB 090618
  9. GRB 090621B: Fermi GBM detection
  10. GRB 090621B: Gemini spectrum of afterglow candidate
  11. GRB 090621B: P60 Observations
  12. GRB 090621: Fermi GBM observation
  13. GRB 090621B: VLA observations
  14. Konus-Wind and Konus-RF observations of GRB 090618
  15. GRB 090621B: Swift/UVOT Upper Limits
  16. GRB 090621B: Swift-BAT refined analysis
  17. GRB 090621B: Swift-XRT refined analysis
  18. GRB 090621B: RTT150 optical observations
  19. GRB 090618: RTT150 optical observations
  20. GRB 090621B: Optical Observations
  21. GRB 090621A: Swift-BAT refined analysis
  22. GRB 090621: Swift/UVOT Upper Limits
  23. GRB 090621: Swift-XRT Team refined analysis
  24. GRB090618: Spectrum and photometry from 6.0m BTA
  25. GRB 090618: BOAO V-band Observation
  26. GRB 090618: ZTSh optical observations
  27. GRB 090618 : WSRT radio detection
  28. GRB090618, underlying supernova search
  29. GRB090618: OAA-OAUV Optical observations
  30. GRB 090618: Fermi GBM observation
  31. GRB 090618, Swift-BAT refined spectral analysis
  32. VLA radio detection of GRB 090618
  33. GRB090618 - Continued optical monitoring and light curve break
  34. GRB 090618: Swift-BAT refined analysis
  35. GRB 090618: SARA observations
  36. GRB090618: Swift-XRT team refined analysis
  37. GRB090618: Swift/UVOT bright afterglow detection
  38. GRB 090618: SDSS host detection
  39. Swift XRT observations of GRB 090531A
  40. GRB 090618: AGILE observations
  41. GRB 090618: LOAO R-band Observation
  42. GRB 090618 Faulkes Telescope North observations
  43. Optical observations of GRB 090618
  44. GRB 090618: OA behavior from KAIT
  45. GRB 090618: ROTSE-III Detection of Optical Counterpart
  46. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  47. GRB 090424: WSRT Radio Observations
  48. GRB 090423: WSRT Radio Observations
  49. RXTE Discovery of Pulsations from SGR 0418+5729
  50. GRB 090531B: Fermi GBM detection
  51. Konus-RF observation of SGR burst 090605A
  52. Discovery of a new soft gamma repeater source, SGR 0418+5729
  53. GRB 090607: XRT Team Refined Analysis
  54. GRB 090607: Swift/UVOT Upper Limits
  55. GRB 090607: Swift-BAT refined analysis of the SHB
  56. GRB 090607: GRAS001 optical observations
  57. GRB 090607: Faulkes Telescope North observations
  58. Ignore GCN/Swift-BAT Lightcurve Notices for trigger 353567
  59. GRB 090530B: Suzaku WAM observation of the prompt emission
  60. GRB 090530: Further NOT optical observations
  61. GRB 090530: RTT150 Optical Observation
  62. GRB 090529A: RTT150 Optical Observations
  63. GMRT observation of GRB 090424 afterglow
  64. GRB 090528: Suzaku WAM observation of the prompt emission
  65. GRB090529: Further NOT optical observations
  66. GRB 090531b, SMARTS optical/IR observations
  67. GRB 090531B: GROND observation
  68. GRB 090530: Early RAPTOR Optical Observations
  69. GRB090529B: ROVOR Upper Limits
  70. GRB 090531A: SARA upper limit
  71. GRB 090531B: Swift/BAT spectral lag results
  72. Corrections to GRB 090531B Swift/UVOT Upper Limits
  73. GRB 090531B, RIMOTS optical upper limits
  74. GRB 090531B: Swift/UVOT Upper Limits
  75. GRB 090528B: MASTER-II Kourovka optical limit
  76. GRB 090529: MITSuME optical observation
  77. GRB 090530: GRT Optical Observation
  78. GRB 090531B: Swift-BAT refined analysis
  79. Initial Swift/UVOT observations of GRB 090531B
  80. GRB 090531B: Swift-XRT candidate afterglow position
  81. GRB 090531B: ROTSE-III Optical Limits
  82. GRB 090531: Swift-BAT refined analysis
  83. GRB090530: R-band Observation
  84. GRB 090530: break in light curve
  85. GRB 090529: VLT spectroscopic redshift
  86. GRB 090531: GROND upper limits
  87. GRB 090531: P60 Observations
  88. GRB 090529: NOT optical observations
  89. GRB 090530: NOT optical observations
  90. GRB090530: Swift XRT refined analysis
  91. GRB090530: Swift/UVOT afterglow detection
  92. GRB 090529: Swift-XRT refined analysis
  93. GRB 090529: OSN optical observations
  94. Strong radio emission from SN 2007bg one year after the explosion - detection of spreading, off-axis GRB jet?
  95. GRB 090530: Swift-BAT refined analysis
  96. GRB 090530: GRAS002 refined OA analysis
  97. GRB 090530: GRAS002 optical observations
  98. GRB 090530: PAIRITEL NIR Detections
  99. GRB 090530A: ROTSE-III Detection of Optical Counterpart
  100. GRB 090529: optical observations

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