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

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