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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"

35268 results found.

  1. GRB 060209(?): Swift-BAT detection of a possible burst
  2. GRB 060206: near-infrared observations (JK' imaging)
  3. GRB 060206: WSRT Radio Observations
  4. GRB 060203: Swift/UVOT upper limits
  5. GRB 060206: TTT Observations
  6. GRB 060206: More PROMPT Detections
  7. GRB 060121 : WIDGET Pre-trigger limit
  8. GRB 060206: Tenagra II Observations
  9. GRB 060206: PROMPT Detections
  10. Retraction of orphan GRB afterglow candidate
  11. GRB060204a: Swift XRT Source is not GRB Afterglow
  12. GRB 060206: optical observations at Asiago
  13. Orphan GRB Afterglow candidate
  14. GRB 060204b: pseudo-z from spectral parameters of the prompt emission
  15. GRB 060206: Subaru/FOCAS optical spectroscopy
  16. GRB 060206: IR Detection of the Afterglow
  17. GRB 060206: Lick 3m Spectroscopy
  18. GRB 060204A: ROSAT Pointing
  19. GRB 060206: Super-LOTIS observations
  20. GRB060204A: Swift/UVOT observations
  21. GRB 060206: Swift-BAT refined analysis
  22. GRB 060206 : Lulin optical observations
  23. GRB060206: SDSS Pre-Burst Observations
  24. GRB060206: Swift XRT Refined Analysis
  25. GRB060206: Liverpool Telescope observation
  26. GRB 060206: Spectroscopic Redshift
  27. GRB060206: P60 Optical Observations
  28. GRB 060206: KAIT observations
  29. GRB060206: Swift XRT Position
  30. GRB060206: SARA Detection
  31. GRB 060206: RAPTOR observations of afterglow candidate variability.
  32. GRB 060206: High redshift burst
  33. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  34. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  35. BAT GRB 060204C is probably not a GRB
  36. GRB060204C: optical observation
  37. GRB 060204B: BVRi-band detections of optical afterglow
  38. GRB 060204A: Swift XRT upper limit
  39. GRB 060204A: FRAM optical observations
  40. GRB060204B: Swift/UVOT refined analysis
  41. GRB 060204C: optical observations
  42. Swift XRT Observation of GRB 060204C
  43. GRB 060204B: Swift-BAT refined analysis
  44. GRB 060204B: ART early limit
  45. GRB060204B: Swift XRT Team Refined Analysis
  46. GRB 060204C: OSN limits
  47. GRB 060204b: Keck/LRIS Afterglow Confirmation
  48. GRB 060204C: BOOTES-IR optical limits
  49. GRB 060204C: Liverpool Telescopes optical limit
  50. GRB 060204C: ROTSE-III Optical Limits
  51. GRB 060204C: Swift-BAT detection of a burst
  52. GRB 060124: Radio Observations
  53. GRB060204B: Faulkes OT candidate
  54. GRB 060204B: ART optical limit
  55. GRB 060204A: further INTEGRAL results
  56. GRB060204B - SDSS pre-burst observations
  57. GRB 060203: Swift-BAT refined analysis
  58. GRB 060204B: Swift detection of a burst
  59. GRB 060204: a long GRB detected by INTEGRAL
  60. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  61. GRB 060203: RTT150 optical observations
  62. GRB060203: Swift XRT Team Refined Analysis
  63. Swift-BAT trigger is GRB 060203
  64. GRB 060203: IR Counterpart
  65. GRB060203: Observations with SARA
  66. GRB 060203: P60 Confirmation of Optical Afterglow
  67. Possible GRB 060203: candidate optical counterpart
  68. Possible GRB 060203: optical observations at Asiago
  69. GRB 060202: PROMPT Observations
  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. GRB 060202: Swift/UVOT upper limits
  77. GRB 060202: Swift XRT Team Refined Analysis
  78. GRB 060202 : Lulin R and I band limit
  79. GRB060202: Faulkes North observation
  80. GRB 060202: Swift detection of a burst
  81. GRB 060121: Gemini Late-time Observations
  82. Erratum: SDSS pre-burst observations of GRB fields
  83. GRB 060130: PROMPT Observations
  84. GRB 060130: Swift/XRT observation
  85. GRB 051211A: MDM Observations
  86. GRB 060123: Gemini spectroscopy of the putative host galaxy
  87. GRB 060123: VLA Radio Observations
  88. GRB060130: Optical imaging
  89. GRB060130: REM infrared observations
  90. GRB 060130, SMARTS optical observations
  91. GRB 060130: FRAM optical observations
  92. GRB 060130: further INTEGRAL IBIS results
  93. GRB 060130: a long GRB detected with INTEGRAL
  94. Possible GRB 051221B: MDM Correction
  95. GRB050121: optical observation
  96. GRB050121b: optical observation
  97. GRB 060121: Confirmation of NIR Afterglow
  98. GRB060124: optical observation
  99. GRB060124: optical observations
  100. GRB 060123: Swift refined analysis of an unusual GRB

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