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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"

4942 results found.

  1. GRB060319: MASTER limit
  2. GRB060319: MASTER optical observation
  3. GRB 060313: Swift/UVOT Observations
  4. GRB 060313, SMARTS optical/IR observations
  5. GRB 060312: Swift detection of a burst
  6. GRB060218: analysis of the XMM-Newton observation
  7. GRB 060218/SN 2006aj: WIRO optical observations
  8. GRB 060218/SN 2006aj: RBO optical observations
  9. GRB 060218: Refined analysis of the radio afterglow
  10. GRB 060218: optical/nIR observations at La Palma
  11. GRB 060218A: ROTSE-III Possible Optical Flare
  12. Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
  13. GRB060218 : SDSS pre-burst observations
  14. GRB 060218: Swift XRT Position
  15. GRB 060218: Swift-BAT detection of a possible burst
  16. GRB 060211b: WIRO NIR Observations
  17. GRB 060211a: WIRO NIR Observations
  18. GRB 050826: Optical Afterglow and Host Galaxy
  19. GRB 060211A: Swift XRT Team Refined Analysis
  20. GRB060210:Faulkes Telescope North Afterglow Confirmation
  21. GRB 060210: candidate afterglow
  22. GRB060210: Optical afterglow
  23. Orphan GRB Afterglow candidate
  24. GRB060206: Swift XRT Refined Analysis
  25. GRB060206: P60 Optical Observations
  26. GRB060206: Swift XRT Position
  27. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  28. GRB 060203: RTT150 optical observations
  29. GRB 060203: P60 Confirmation of Optical Afterglow
  30. GRB 060202: Gemini-N J, H, K_s observations
  31. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  32. GRB 060121: I-band Limits
  33. GRB060121: SARA Observations
  34. GRB 060117: PROMPT Observations
  35. GRB 060116: PROMPT Observations
  36. GRB 060115: PROMPT Observations
  37. GRB 060114: Swift/UVOT Observations
  38. GRB 060115: MITSuME optical afterglow candidate
  39. GRB060111A: RTT150 optical observations
  40. GRB 060110: Optical limit
  41. Swift-BAT trigger 175653 is not an astrophysical source
  42. Swift-BAT trigger 175653 is probably not a GRB
  43. GRB 051227: MDM Observation
  44. Swift-BAT detection of a possible burst
  45. GRB 051221: Improved astrometry of the IR counterpart
  46. GRB051211b: P60 Observations
  47. Possible resuming of the SGR 1806-20 activity
  48. GRB 051117B,optical observation
  49. GRB 051111: Keck HIRES redshift
  50. GRB051111: Swift-BAT detection of a bright burst
  51. GRB051109B: no UVOT source detected
  52. GRB 051109B: Swift detection of a burst
  53. GRB 051109: HET Optical Spectrum and Absorption Redshift
  54. GRB 051109A: ROTSE-III Decline rate for Optical Counterpart
  55. GRB051105B: Swift/XRT upper limit
  56. GRB051103: MASTER: OT limit and host galaxy candidates
  57. GRB051103:_MASTER_optical_observations
  58. GRB051028:MASTER observations
  59. GRB051021.63
  60. Swift-BAT trigger 160640 is not a real GRB
  61. GRB051021: A GRB Localized by HETE
  62. GRB050925: Swift UVOT upper limits
  63. GRB 050916: XRT position
  64. Swift is in normal operation
  65. GRB 050906: Possible X-ray Counterpart
  66. GRB 050906: Radio Observations
  67. GRB050904: Optical Observations
  68. Swift-BAT triggers 153461-153465 are not GRBs
  69. Retraction of Swift-BAT trigger #153355
  70. GRB050827: Swift-BAT detection of a burst
  71. GRB050822: Swift/UVOT upper limits
  72. GRB 050822: Swift-BAT refined analysis
  73. GRB 050822: ROTSE-III Prompt Optical Limits
  74. GRB 050822: Swift detection of a long burst
  75. GRB050820B: Planned XMM-Newton observation
  76. GRB050820B: BAT-Swift detection of a bright GRB
  77. GRB050813, SDSS pre-burst observations
  78. RBO GRB 050714A and GRB 050716 observations
  79. GRB050730: Radio Detection
  80. GRB 050730, corrected photometry and break?
  81. GRB050801: Swift-BAT detection of a burst
  82. GRB 050730, spectra and optical photometry
  83. GRB 050730: Swift XRT afterglow observations
  84. GRB050730, afterglow observations
  85. GRB 050730 : Planned XMM-Newton observation
  86. GRB050730: Liverpool Telescope optical observations
  87. GRB 050730, optical candidate
  88. GRB 050724, SMARTS optical/IR afterglow observations
  89. GRB050726: Swift-BAT detection of a weak burst
  90. GRB 050715: Swift-BAT detection
  91. Swift detection of a long transient (GRB 050714B?)
  92. GRB 050712: Swift XRT afterglow position
  93. GRB 050712: Swift detection of a weak burst
  94. GRB 050626: Swift XRT observations
  95. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  96. GRB 050626 - a long GRB detected with INTEGRAL
  97. GRB 050603: INTEGRAL shows it is not a short GRB
  98. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  99. GRB 050525: MITSuME Optical Observation in VRI
  100. GRB 050525A: BOOTES simultaneous optical observations

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