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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"

36947 results found.

  1. GRB 060121 : WIDGET Pre-trigger limit
  2. GRB 060206: Tenagra II Observations
  3. GRB 060206: PROMPT Detections
  4. Retraction of orphan GRB afterglow candidate
  5. GRB060204a: Swift XRT Source is not GRB Afterglow
  6. GRB 060206: optical observations at Asiago
  7. Orphan GRB Afterglow candidate
  8. GRB 060204b: pseudo-z from spectral parameters of the prompt emission
  9. GRB 060206: Subaru/FOCAS optical spectroscopy
  10. GRB 060206: IR Detection of the Afterglow
  11. GRB 060206: Lick 3m Spectroscopy
  12. GRB 060204A: ROSAT Pointing
  13. GRB 060206: Super-LOTIS observations
  14. GRB060204A: Swift/UVOT observations
  15. GRB 060206: Swift-BAT refined analysis
  16. GRB 060206 : Lulin optical observations
  17. GRB060206: SDSS Pre-Burst Observations
  18. GRB060206: Swift XRT Refined Analysis
  19. GRB060206: Liverpool Telescope observation
  20. GRB 060206: Spectroscopic Redshift
  21. GRB060206: P60 Optical Observations
  22. GRB 060206: KAIT observations
  23. GRB060206: Swift XRT Position
  24. GRB060206: SARA Detection
  25. GRB 060206: RAPTOR observations of afterglow candidate variability.
  26. GRB 060206: High redshift burst
  27. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  28. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  29. GRB060206: Swift-BAT detection of a burst
  30. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  31. BAT GRB 060204C is probably not a GRB
  32. GRB060204C: optical observation
  33. GRB 060204B: BVRi-band detections of optical afterglow
  34. GRB 060204A: Swift XRT upper limit
  35. GRB 060204A: FRAM optical observations
  36. GRB060204B: Swift/UVOT refined analysis
  37. GRB 060204C: optical observations
  38. Swift XRT Observation of GRB 060204C
  39. GRB 060204B: Swift-BAT refined analysis
  40. GRB 060204B: ART early limit
  41. GRB060204B: Swift XRT Team Refined Analysis
  42. GRB 060204C: OSN limits
  43. GRB 060204b: Keck/LRIS Afterglow Confirmation
  44. GRB 060204C: BOOTES-IR optical limits
  45. GRB 060204C: Liverpool Telescopes optical limit
  46. GRB 060204C: ROTSE-III Optical Limits
  47. GRB 060204C: Swift-BAT detection of a burst
  48. GRB 060124: Radio Observations
  49. GRB060204B: Faulkes OT candidate
  50. GRB 060204B: ART optical limit
  51. GRB 060204A: further INTEGRAL results
  52. GRB060204B, optical observation
  53. GRB060204B - SDSS pre-burst observations
  54. GRB 060203: Swift-BAT refined analysis
  55. GRB 060204B: Swift detection of a burst
  56. GRB 060204: a long GRB detected by INTEGRAL
  57. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  58. GRB 060203: RTT150 optical observations
  59. GRB060203: Swift XRT Team Refined Analysis
  60. GRB060203 - Swift UVOT observation
  61. Swift-BAT trigger is GRB 060203
  62. GRB 060203: IR Counterpart
  63. GRB060203: Observations with SARA
  64. GRB 060203: P60 Confirmation of Optical Afterglow
  65. Possible GRB 060203: candidate optical counterpart
  66. Swift BAT Trigger 180151: Swift XRT source detection
  67. Possible GRB 060203: optical observations at Asiago
  68. GRB 060202: PROMPT Observations
  69. Swift-BAT trigger 180151 is unknown origin at this time
  70. GRB 060202: GETS observation
  71. GRB 060202: Gemini-N J, H, K_s observations
  72. GRB 060202 : Kiso B and R band limit
  73. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  74. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  75. GRB 060202: Refined analysis of the Swift-BAT burst
  76. GRB060202, optical observation
  77. GRB 060202: Swift/UVOT upper limits
  78. GRB 060202: Swift XRT Team Refined Analysis
  79. GRB 060202 : Lulin R and I band limit
  80. GRB060202: Faulkes North observation
  81. GRB 060202: Swift detection of a burst
  82. GRB 060121: Gemini Late-time Observations
  83. Erratum: SDSS pre-burst observations of GRB fields
  84. GRB 060130: PROMPT Observations
  85. GRB 060130: Swift/XRT observation
  86. GRB 051211A: MDM Observations
  87. GRB 060123: Gemini spectroscopy of the putative host galaxy
  88. GRB 060123: VLA Radio Observations
  89. GRB060130: Optical imaging
  90. GRB060130: REM infrared observations
  91. GRB 060130, SMARTS optical observations
  92. GRB 060130: FRAM optical observations
  93. GRB 060130: further INTEGRAL IBIS results
  94. GRB 060130: a long GRB detected with INTEGRAL
  95. Possible GRB 051221B: MDM Correction
  96. GRB050121: optical observation
  97. GRB050121b: optical observation
  98. GRB 060121: Confirmation of NIR Afterglow
  99. GRB060124: optical observation
  100. GRB060124: optical observations

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