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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"
  1. GRB 080325: Subaru detection of NIR afterglow candidate
  2. GRB080310, late-time photometry with LBT
  3. GRB 080325: MITSuME Akeno optical upper limits
  4. GRB080325: XRT Refined Analysis
  5. GRB 080325: GROND Observations
  6. GRB080319B: optical observations
  7. GRB 080325: Swift/UVOT Upper Limits
  8. GRB 080319C: Gemini-North spectroscopic redshift
  9. GRB 080325: Early observations from OSN
  10. GRB 080325: NIR afterglow candidate
  11. GRB 080319D: GROND Detection of the Optical Counterpart
  12. GRB 080325: Enhanced Swift-XRT position
  13. GRB 080325: Swift detection of a burst
  14. GRB 080319B : Apparent spectral evolution in very early Swift/XRT WT mode data: intrinsic or pile-up effect?
  15. IBAS Alert n. 5245: NOT a GRB
  16. GRB 080319B: Spitzer Mid-infrared Observations
  17. GRB 080319C: Suzaku WAM observation of the prompt emission
  18. GRB 080319B: Second & Third Epoch WSRT Radio Observations
  19. Radio Detection of GRB 080319B
  20. GRB 080320, Swift-BAT refined analysis
  21. GRB 080319B: Optical observation (Brno, CZ)
  22. GRB 080319D: GROND Observations
  23. GRB 080319B: TORTORA light curve
  24. GRB 080319B: optical upper limit
  25. GRB 080319D: optical upper limit
  26. GRB080319B: Time-Independent XRT Spectrum
  27. GRB 080319D, Swift-BAT refined analysis
  28. GRB 080319C: UVOT Observations
  29. GRB 080319B: UVOT Observations
  30. GRB 080319A: UVOT Observations
  31. GRB 080320: Swift XRT refined analysis
  32. GRB 080319B - CARMA mm Observations
  33. GRB 080320: Early Super-LOTIS Observations
  34. GRB 080320: J detection with FLAMINGOS
  35. GRB 080319D: Swift XRT refined analysis
  36. GRB 080320: optical limit
  37. GRB 080320: Gemini-N optical afterglow
  38. Konus-Wind observation of GRB 080319C
  39. GRB 080319B: Gemini-South photometry
  40. GRB 080319B: Allen Telescope Array Observations
  41. GRB 080319B optical observations
  42. GRB 080319C, Swift-BAT refined analysis
  43. Konus-Wind observation of GRB 080319B
  44. GRB 080319B: WSRT Radio Observations
  45. GRB 080320: SDSS source and Gemini-N observations
  46. GRB 080320: Enhanced Swift-XRT position
  47. GRB 080320: optical limit from IAC80
  48. GRB 080319C: Early RAPTOR Observations
  49. GRB 080319B: second epoch imaging from Canarias (correction to GCN7469)
  50. GRB 080319C: KAIT OA observations
  51. GRB 080320 - SDSS Pre-Burst Observations
  52. GRB 080320: Swift detection of a burst
  53. GRB 080320: ROTSE-III Optical Limits
  54. GRB 080319B : Lulin observation of temporal break at 0.2 days
  55. GRB 080319B: ROTSE-III Observations of Optical Counterpart
  56. GRB 080319B: optical observations
  57. GRB 080319C - SDSS Pre-Burst Observations
  58. GRB 080319A SDSS Pre-Burst Observations
  59. Swift-BAT trigger 306829 is IGR J16479-4514
  60. GRB080319B - SDSS Pre-Burst Observations
  61. GRB 080319B: RAPTOR observations of a naked eye burst
  62. GRB 080319A: Swift-XRT Team Refined Analysis
  63. GRB 080319B, Swift-BAT refined analysis
  64. GRB080319B: Prompt PROMPT Detections
  65. GRB 080319C: Swift-XRT Team Refined Analysis
  66. GRB 080319B: Swift-XRT Team Refined Analysis
  67. GRB 080319D: Swift/UVOT Refined Analysis of the Fading Optical Afterglow Candidate
  68. GRB 080319C: AGILE-MCAL observation of the prompt emission
  69. GRB 080319B: Hobby-Eberly Telescope Spectroscopy
  70. GRB 080319D: MASTER-VWF-Kislovodsk optical observation
  71. GRB 080319C: MASTER-VWF-Kislovodsk optical observation
  72. GRB 080319D: Swift detection of a burst with a possible optical afterglow
  73. GRB 080319B: TORTORA synchronous observation
  74. VLT/UVES redshift of GRB 080319B from FeII fine-structure lines
  75. GRB 080319A/B/C: INTEGRAL SPI-ACS light curves available
  76. GRB 080319B: Enhanced Swift-XRT position
  77. GRB 080319A: Enhanced Swift-XRT position
  78. GRB 080319A, Swift-BAT refined analysis
  79. GRB 080319B: REM early data
  80. GRB 080319b light curve by Pi-of-the-Sky
  81. VLT/UVES redshift of GRB 080319B
  82. GRB 080319C: Early Super-LOTIS Observations
  83. GRB 080319C: Swift detection of a burst with an optical afterglow
  84. GRB 080319C: KAIT OA candidate
  85. GRB 080319A: REM observations
  86. GRB 080319b prompt optical observation by Pi-of-the-Sky
  87. GRB 080319B: Change in power law decay index
  88. GRB 080319B: Gemini-South Spectroscopy
  89. GRB 080319A: optical observations at the NOT
  90. GRB0 080319B : LOAO optical observation
  91. GRB 080319b: Early IR Imaging from PAIRITEL
  92. GRB080319B Liverpool Telescope optical afterglow candidate
  93. GRB 080319B: Super-LOTIS Detection of a Bright OT
  94. GRB 080319B: REM observations
  95. GRB 080319B: KAIT OA
  96. GRB080319A: P60 Optical Afterglow Observations
  97. GRB 080319B: UVOT Position
  98. GRB 080319B: Swift detection of an intense burst with a bright optical counterpart
  99. GRB 080319A: Swift detection of a burst
  100. Swift Trigger 306745 is not a GRB

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