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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"

5052 results found.

  1. SGR 1900+14: Swift-BAT detection of a bright outburst
  2. GRB 060322: Confirmation of Swift XRT afterglow
  3. GRB 060211A: optical observation
  4. SGR 1900+14: Refined Swift-BAT analysis of the renewed activity
  5. GRB 060322: Swift XRT afterglow candidate
  6. GRB 060323: Swift/UVOT Observations
  7. GRB 060323: Swift XRT refined analysis
  8. GRB060218/SN2006aj: optical observations
  9. GRB060319: Swift XRT refined analysis
  10. GRB060319: Swift/UVOT upper limits
  11. GRB060319: MASTER limit
  12. GRB060319: MASTER optical observation
  13. GRB 060313: Swift/UVOT Observations
  14. GRB 060313, SMARTS optical/IR observations
  15. GRB 060312: Swift detection of a burst
  16. GRB060218: analysis of the XMM-Newton observation
  17. GRB 060218/SN 2006aj: WIRO optical observations
  18. GRB 060218/SN 2006aj: RBO optical observations
  19. GRB 060218: Refined analysis of the radio afterglow
  20. GRB 060218: optical/nIR observations at La Palma
  21. GRB 060218A: ROTSE-III Possible Optical Flare
  22. Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
  23. GRB060218 : SDSS pre-burst observations
  24. GRB 060218: Swift XRT Position
  25. GRB 060218: Swift-BAT detection of a possible burst
  26. GRB 060211b: WIRO NIR Observations
  27. GRB 060211a: WIRO NIR Observations
  28. GRB 050826: Optical Afterglow and Host Galaxy
  29. GRB 060211A: Swift XRT Team Refined Analysis
  30. GRB060210:Faulkes Telescope North Afterglow Confirmation
  31. GRB 060210: candidate afterglow
  32. GRB060210: Optical afterglow
  33. Orphan GRB Afterglow candidate
  34. GRB060206: Swift XRT Refined Analysis
  35. GRB060206: P60 Optical Observations
  36. GRB060206: Swift XRT Position
  37. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  38. GRB 060203: RTT150 optical observations
  39. GRB 060203: P60 Confirmation of Optical Afterglow
  40. GRB 060202: Gemini-N J, H, K_s observations
  41. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  42. GRB 060121: I-band Limits
  43. GRB060121: SARA Observations
  44. GRB 060117: PROMPT Observations
  45. GRB 060116: PROMPT Observations
  46. GRB 060115: PROMPT Observations
  47. GRB 060114: Swift/UVOT Observations
  48. GRB 060115: MITSuME optical afterglow candidate
  49. GRB060111A: RTT150 optical observations
  50. GRB 060110: Optical limit
  51. Swift-BAT trigger 175653 is not an astrophysical source
  52. Swift-BAT trigger 175653 is probably not a GRB
  53. GRB 051227: MDM Observation
  54. Swift-BAT detection of a possible burst
  55. GRB 051221: Improved astrometry of the IR counterpart
  56. GRB051211b: P60 Observations
  57. Possible resuming of the SGR 1806-20 activity
  58. GRB 051117B,optical observation
  59. GRB 051111: Keck HIRES redshift
  60. GRB051111: Swift-BAT detection of a bright burst
  61. GRB051109B: no UVOT source detected
  62. GRB 051109B: Swift detection of a burst
  63. GRB 051109: HET Optical Spectrum and Absorption Redshift
  64. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  65. GRB051105B: Swift/XRT upper limit
  66. GRB051103: MASTER: OT limit and host galaxy candidates
  67. GRB051103:_MASTER_optical_observations
  68. GRB051028:MASTER observations
  69. GRB051021.63
  70. Swift-BAT trigger 160640 is not a real GRB
  71. GRB051021: A GRB Localized by HETE
  72. GRB050925: Swift UVOT upper limits
  73. GRB 050916: XRT position
  74. Swift is in normal operation
  75. GRB 050906: Possible X-ray Counterpart
  76. GRB 050906: Radio Observations
  77. GRB050904: Optical Observations
  78. Swift-BAT triggers 153461-153465 are not GRBs
  79. Retraction of Swift-BAT trigger #153355
  80. GRB050827: Swift-BAT detection of a burst
  81. GRB050822: Swift/UVOT upper limits
  82. GRB 050822: Swift-BAT refined analysis
  83. GRB 050822: ROTSE-III Prompt Optical Limits
  84. GRB 050822: Swift detection of a long burst
  85. GRB050820B: Planned XMM-Newton observation
  86. GRB050820B: BAT-Swift detection of a bright GRB
  87. GRB050813, SDSS pre-burst observations
  88. RBO GRB 050714A and GRB 050716 observations
  89. GRB050730: Radio Detection
  90. GRB 050730, corrected photometry and break?
  91. GRB050801: Swift-BAT detection of a burst
  92. GRB 050730, spectra and optical photometry
  93. GRB 050730: Swift XRT afterglow observations
  94. GRB050730, afterglow observations
  95. GRB 050730 : Planned XMM-Newton observation
  96. GRB050730: Liverpool Telescope optical observations
  97. GRB 050730, optical candidate
  98. GRB 050724, SMARTS optical/IR afterglow observations
  99. GRB050726: Swift-BAT detection of a weak burst
  100. GRB 050715: Swift-BAT detection

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