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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"

35344 results found.

  1. GRB 060204C: optical observations
  2. Swift XRT Observation of GRB 060204C
  3. GRB 060204B: Swift-BAT refined analysis
  4. GRB 060204B: ART early limit
  5. GRB060204B: Swift XRT Team Refined Analysis
  6. GRB 060204C: OSN limits
  7. GRB 060204b: Keck/LRIS Afterglow Confirmation
  8. GRB 060204C: BOOTES-IR optical limits
  9. GRB 060204C: Liverpool Telescopes optical limit
  10. GRB 060204C: ROTSE-III Optical Limits
  11. GRB 060204C: Swift-BAT detection of a burst
  12. GRB 060124: Radio Observations
  13. GRB060204B: Faulkes OT candidate
  14. GRB 060204B: ART optical limit
  15. GRB 060204A: further INTEGRAL results
  16. GRB060204B - SDSS pre-burst observations
  17. GRB 060203: Swift-BAT refined analysis
  18. GRB 060204B: Swift detection of a burst
  19. GRB 060204: a long GRB detected by INTEGRAL
  20. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  21. GRB 060203: RTT150 optical observations
  22. GRB060203: Swift XRT Team Refined Analysis
  23. Swift-BAT trigger is GRB 060203
  24. GRB 060203: IR Counterpart
  25. GRB060203: Observations with SARA
  26. GRB 060203: P60 Confirmation of Optical Afterglow
  27. Possible GRB 060203: candidate optical counterpart
  28. Possible GRB 060203: optical observations at Asiago
  29. GRB 060202: PROMPT Observations
  30. GRB 060202: GETS observation
  31. GRB 060202: Gemini-N J, H, K_s observations
  32. GRB 060202 : Kiso B and R band limit
  33. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  34. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  35. GRB 060202: Refined analysis of the Swift-BAT burst
  36. GRB 060202: Swift/UVOT upper limits
  37. GRB 060202: Swift XRT Team Refined Analysis
  38. GRB 060202 : Lulin R and I band limit
  39. GRB060202: Faulkes North observation
  40. GRB 060202: Swift detection of a burst
  41. GRB 060121: Gemini Late-time Observations
  42. Erratum: SDSS pre-burst observations of GRB fields
  43. GRB 060130: PROMPT Observations
  44. GRB 060130: Swift/XRT observation
  45. GRB 051211A: MDM Observations
  46. GRB 060123: Gemini spectroscopy of the putative host galaxy
  47. GRB 060123: VLA Radio Observations
  48. GRB060130: Optical imaging
  49. GRB060130: REM infrared observations
  50. GRB 060130, SMARTS optical observations
  51. GRB 060130: FRAM optical observations
  52. GRB 060130: further INTEGRAL IBIS results
  53. GRB 060130: a long GRB detected with INTEGRAL
  54. Possible GRB 051221B: MDM Correction
  55. GRB050121: optical observation
  56. GRB050121b: optical observation
  57. GRB 060121: Confirmation of NIR Afterglow
  58. GRB060124: optical observation
  59. GRB060124: optical observations
  60. GRB 060123: Swift refined analysis of an unusual GRB
  61. GRB060124, BVRcIc field calibration
  62. GRB060105: refined analysis of the Suzaku observation
  63. GRB060124 optical observations
  64. GRB 060121: Probable Detection of NIR Afterglow
  65. GRB060124: optical observation
  66. GRB 060116 HST observations
  67. GRB 060124: HETE detection and spectrum of the main peak
  68. Refined XRT Position for GRB 060123
  69. Konus-Wind observation of GRB 060124
  70. GRB060124: detailed XRT analysis
  71. GRB 060124 Optical Observations
  72. GRB 060124: ART optical limits during the burst
  73. GRB060123: Optical and IR Imaging
  74. GRB 060123: P200 Observations
  75. GRB 060124: Keck optical spectrum
  76. GRB 060124: Keck Absorption Redshift
  77. GRB 060124: MDM Optical Spectrum
  78. GRB 060124: XRT refined analysis
  79. GRB 060124: R band Observations
  80. GRB 060124 : Optical observation at Xinglong and Kiso
  81. GRB060124: optical observations at Asiago
  82. GRB 060124: Extremely long burst, Swift-BAT refined analysis
  83. GRB060123: SDSS pre-burst observations
  84. GRB 060123: Swift detection of a very long, faint burst
  85. GRB 060116: Further analysis of VLT photometry and optical spectroscopy
  86. GRB 060121: OHP optical limits
  87. GRB 060124: TAROT optical limits
  88. GRB 060124: Swift/UVOT Observation
  89. GRB 060124: Confirmation of the Afterglow
  90. GRB 060124: XRT position
  91. GRB 060124: Optical Afterglow Candidate from Tautenburg
  92. GRB 050124 : Kiso Optical limit
  93. GRB 060124: Optical Observations at Tautenburg
  94. GRB 060117: Suzaku WAM observation of the prompt emission
  95. GRB060124:MASTER optical observation
  96. GRB 060111B: Suzaku WAM observation of the prompt emission
  97. GRB 060124: Swift-BAT detection of a burst
  98. GRB 060116: Radio Detection
  99. GRB 060116: MARGE optical observations
  100. GRB 060121: Swift/UVOT upper limits

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