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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. Swift Trigger 306745 is not a GRB
  2. Swift Trigger 306616 is not a GRB
  3. GRB080310, LBT and MDM photometry
  4. GRB080315: Bok Optical Observations
  5. Swift/UVOT observations of GRB 080315
  6. Swift trigger 306323: Swift-BAT/XRT refined analysis
  7. SAX J1818.6-1703: Swift detection (trigger 306379)
  8. GRB 080315: Optical observations
  9. GRB 080315: TAROT Calern observatory optical observations
  10. GRB 080315: Swift detection of a possible burst
  11. GRB080310 : Lulin Optical observations
  12. GRB080310, unusual slow decay in the optical
  13. GRB 080310: GAO 150cm telescope Optical Observation
  14. GRB080310 : Optical observations by LOAO and Lulin
  15. GRB 080310: ROTSE-III Observations of Optical Counterpart
  16. GRB080310: Optical observation by MITSuME telescope
  17. GRB080310, optical observations with the LBT
  18. GRB 080307: GAO 150cm telescope Optical Observation
  19. GRB 080229A: GAO 150cm telescope Optical Observation
  20. GRB 080310: PAIRITEL detection and PAIRITEL+KAIT+UVOT SED
  21. GRB 080307: NIR upper limit
  22. GRB 080229: NIR upper limit
  23. GRB 080310: early RAPTOR multicolor observations
  24. GRB 080310, Swift-BAT refined analysis
  25. GRB080210: optical observations
  26. GRB080307: optical upper limit
  27. GRB 080310: Swift-XRT refined analysis
  28. GRB 080310: Swift/UVOT Refined Analysis
  29. GRB 080310: Redshift from Keck/DEIMOS Spectra
  30. GRB 080310 - SDSS Pre-Burst Observations
  31. GRB080310 : Lulin optical observation
  32. GRB 080310: Enhanced Swift-XRT position
  33. GRB 080310: RRM optical photometry with the VLT
  34. GRB080310, detection of break in optical
  35. GRB 080310: VLT/UVES spectroscopy
  36. GRB080310, optical observations with LBT
  37. GRB 080310: Magellan redshift revision
  38. GRB 080310: Lick/Kast Spectroscopy
  39. GRB080310: Super-LOTIS suggestion of brightening
  40. GRB 080310, SMARTS optical/IR afterglow observations
  41. GRB 080310: REM observations
  42. GRB 080310: Magellan redshift
  43. GRB 080310 afterglow candidate (correction to UT time)
  44. GRB 080310: Swift detection of a burst with optical afterglow
  45. GRB 080310 afterglow candidate
  46. GRB080229, optical upper limit (Correction)
  47. GRB080307, optical upper limit
  48. GRB080307 BOAO optical afterglow observation - detection of a possible OT
  49. GRB080229, optical upper limit
  50. GRB 080307: Swift-XRT Team refined analysis
  51. GRB 080307: Swift/UVOT Upper Limits
  52. GRB 080307: Early RAPTOR Limits
  53. GRB 080307, Swift-BAT refined analysis
  54. GRB080307 - SDSS Pre-Burst Observations
  55. GRB 080307: TNT optical observation
  56. GRB080307: Optical upper limits
  57. GRB 080307: Gemini-N i-band observations - candidate afterglow
  58. GRB 080307: BOAO imaging - retraction and new limit
  59. GRB 080307: retraction of UVOT candidate
  60. GRB 080307: Enhanced Swift-XRT position
  61. GRB 080307, Preliminary Swift-BAT refined analysis
  62. GRB 080307 : BOAO optical afterglow observation
  63. GRB 080307: Optical observation with DMC/KANATA
  64. GRB 080307: Swift detection of a burst
  65. VLA possible radio detection of GRB 080229
  66. GRB 080303: Swift/UVOT follow-up of afterglow detection
  67. GRB 080303, Swift-BAT refined analysis
  68. GRB 080303: Rapid PROMPT Detections
  69. GRB080303: Swift XRT refined analysis
  70. GRB 080303: Enhanced Swift-XRT position
  71. Swift UVOT observations of GRB080229B
  72. GRB080229B: Swift XRT afterglow observation
  73. GRB 080303A: Faulkes Telescope South optical afterglow observations
  74. GRB 080303
  75. GRB 080303: Swift detection of a burst with optical afterglow
  76. GRB 080303: REM NIR afterglow candidate
  77. GRB 080303A: ROTSE-III Optical Limits
  78. GRB 080229: I-band observations from OSN
  79. GRB 080229: VLT NIR observations
  80. GRB080229: Swift XRT refined analysis
  81. GRB 080229: TNG NIR observations
  82. GRB 080229: Deep Gemini/GMOS optical observations
  83. GRB 080229: Enhanced Swift-XRT position
  84. GRB 080229: REM NIR observations
  85. GRB080229: Possible optical afterglow
  86. GRB 080229B: Gamma Ray Burst Localization by SuperAGILE
  87. UVOT analysis for GRB080229
  88. GRB 080229, Swift-BAT refined analysis
  89. GRB 080229: Faulkes Telescope South optical limit
  90. GRB 080229A: ROTSE-III Optical Limits
  91. GRB 080229: Swift detection of a bright burst
  92. Early optical shallow decay in GRB 071112C
  93. GRB080207: optical observations
  94. GRB080205: optical observations
  95. GRB080211: optical observations
  96. XRF 080109/SN2008D : GMRT upper limit at 1.28 GHz
  97. GRB 071010B : Early optical brightening detected by TAOS
  98. Swift-XRT improved positions, and new redshift limits.
  99. ESO optical and NIR observations of GRB 080218B
  100. GRB 080204: Suzaku WAM observation of the prompt emission

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