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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 080319b prompt optical observation by Pi-of-the-Sky
  2. GRB 080319B: Change in power law decay index
  3. GRB 080319B: Gemini-South Spectroscopy
  4. GRB 080319A: optical observations at the NOT
  5. GRB0 080319B : LOAO optical observation
  6. GRB 080319b: Early IR Imaging from PAIRITEL
  7. GRB080319B Liverpool Telescope optical afterglow candidate
  8. GRB 080319B: Super-LOTIS Detection of a Bright OT
  9. GRB 080319B: REM observations
  10. GRB 080319B: KAIT OA
  11. GRB080319A: P60 Optical Afterglow Observations
  12. GRB 080319B: UVOT Position
  13. GRB 080319B: Swift detection of an intense burst with a bright optical counterpart
  14. GRB 080319A: Swift detection of a burst
  15. Swift Trigger 306745 is not a GRB
  16. Swift Trigger 306616 is not a GRB
  17. GRB080310, LBT and MDM photometry
  18. GRB080315: Bok Optical Observations
  19. Swift/UVOT observations of GRB 080315
  20. Swift trigger 306323: Swift-BAT/XRT refined analysis
  21. SAX J1818.6-1703: Swift detection (trigger 306379)
  22. GRB 080315: Optical observations
  23. GRB 080315: TAROT Calern observatory optical observations
  24. GRB 080315: Swift detection of a possible burst
  25. GRB080310 : Lulin Optical observations
  26. GRB080310, unusual slow decay in the optical
  27. GRB 080310: GAO 150cm telescope Optical Observation
  28. GRB080310 : Optical observations by LOAO and Lulin
  29. GRB 080310: ROTSE-III Observations of Optical Counterpart
  30. GRB080310: Optical observation by MITSuME telescope
  31. GRB080310, optical observations with the LBT
  32. GRB 080307: GAO 150cm telescope Optical Observation
  33. GRB 080229A: GAO 150cm telescope Optical Observation
  34. GRB 080310: PAIRITEL detection and PAIRITEL+KAIT+UVOT SED
  35. GRB 080307: NIR upper limit
  36. GRB 080229: NIR upper limit
  37. GRB 080310: early RAPTOR multicolor observations
  38. GRB 080310, Swift-BAT refined analysis
  39. GRB080210: optical observations
  40. GRB080307: optical upper limit
  41. GRB 080310: Swift-XRT refined analysis
  42. GRB 080310: Swift/UVOT Refined Analysis
  43. GRB 080310: Redshift from Keck/DEIMOS Spectra
  44. GRB 080310 - SDSS Pre-Burst Observations
  45. GRB080310 : Lulin optical observation
  46. GRB 080310: Enhanced Swift-XRT position
  47. GRB 080310: RRM optical photometry with the VLT
  48. GRB080310, detection of break in optical
  49. GRB 080310: VLT/UVES spectroscopy
  50. GRB080310, optical observations with LBT
  51. GRB 080310: Magellan redshift revision
  52. GRB 080310: Lick/Kast Spectroscopy
  53. GRB080310: Super-LOTIS suggestion of brightening
  54. GRB 080310, SMARTS optical/IR afterglow observations
  55. GRB 080310: REM observations
  56. GRB 080310: Magellan redshift
  57. GRB 080310 afterglow candidate (correction to UT time)
  58. GRB 080310: Swift detection of a burst with optical afterglow
  59. GRB 080310 afterglow candidate
  60. GRB080229, optical upper limit (Correction)
  61. GRB080307, optical upper limit
  62. GRB080307 BOAO optical afterglow observation - detection of a possible OT
  63. GRB080229, optical upper limit
  64. GRB 080307: Swift-XRT Team refined analysis
  65. GRB 080307: Swift/UVOT Upper Limits
  66. GRB 080307: Early RAPTOR Limits
  67. GRB 080307, Swift-BAT refined analysis
  68. GRB080307 - SDSS Pre-Burst Observations
  69. GRB 080307: TNT optical observation
  70. GRB080307: Optical upper limits
  71. GRB 080307: Gemini-N i-band observations - candidate afterglow
  72. GRB 080307: BOAO imaging - retraction and new limit
  73. GRB 080307: retraction of UVOT candidate
  74. GRB 080307: Enhanced Swift-XRT position
  75. GRB 080307, Preliminary Swift-BAT refined analysis
  76. GRB 080307 : BOAO optical afterglow observation
  77. GRB 080307: Optical observation with DMC/KANATA
  78. GRB 080307: Swift detection of a burst
  79. VLA possible radio detection of GRB 080229
  80. GRB 080303: Swift/UVOT follow-up of afterglow detection
  81. GRB 080303, Swift-BAT refined analysis
  82. GRB 080303: Rapid PROMPT Detections
  83. GRB080303: Swift XRT refined analysis
  84. GRB 080303: Enhanced Swift-XRT position
  85. Swift UVOT observations of GRB080229B
  86. GRB080229B: Swift XRT afterglow observation
  87. GRB 080303A: Faulkes Telescope South optical afterglow observations
  88. GRB 080303
  89. GRB 080303: Swift detection of a burst with optical afterglow
  90. GRB 080303: REM NIR afterglow candidate
  91. GRB 080303A: ROTSE-III Optical Limits
  92. GRB 080229: I-band observations from OSN
  93. GRB 080229: VLT NIR observations
  94. GRB080229: Swift XRT refined analysis
  95. GRB 080229: TNG NIR observations
  96. GRB 080229: Deep Gemini/GMOS optical observations
  97. GRB 080229: Enhanced Swift-XRT position
  98. GRB 080229: REM NIR observations
  99. GRB080229: Possible optical afterglow
  100. GRB 080229B: Gamma Ray Burst Localization by SuperAGILE

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