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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"

37048 results found.

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

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