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

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