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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"

20958 results found.

  1. GRB 060203: RTT150 optical observations
  2. GRB 060203: IR Counterpart
  3. GRB060203: Observations with SARA
  4. GRB 060203: P60 Confirmation of Optical Afterglow
  5. Possible GRB 060203: candidate optical counterpart
  6. Possible GRB 060203: optical observations at Asiago
  7. GRB 060202: PROMPT Observations
  8. GRB 060202: Gemini-N J, H, K_s observations
  9. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  10. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  11. GRB 060202: Refined analysis of the Swift-BAT burst
  12. GRB 060121: Gemini Late-time Observations
  13. Erratum: SDSS pre-burst observations of GRB fields
  14. GRB 060130: PROMPT Observations
  15. GRB 051211A: MDM Observations
  16. GRB 060123: VLA Radio Observations
  17. GRB060130: REM infrared observations
  18. GRB 060130, SMARTS optical observations
  19. GRB 060130: FRAM optical observations
  20. Possible GRB 051221B: MDM Correction
  21. GRB 060121: Confirmation of NIR Afterglow
  22. GRB060124: optical observations
  23. GRB 060123: Swift refined analysis of an unusual GRB
  24. GRB060124 optical observations
  25. GRB 060121: Probable Detection of NIR Afterglow
  26. GRB 060116 HST observations
  27. GRB 060124 Optical Observations
  28. GRB 060124: ART optical limits during the burst
  29. GRB 060123: P200 Observations
  30. GRB 060124: Keck optical spectrum
  31. GRB 060124: MDM Optical Spectrum
  32. GRB 060124: R band Observations
  33. GRB060124: optical observations at Asiago
  34. GRB060123: SDSS pre-burst observations
  35. GRB 060124: Optical Observations at Tautenburg
  36. GRB 060116: Radio Detection
  37. GRB 060116: MARGE optical observations
  38. GRB 060121: Liverpool Telescopes optical limits
  39. GRB 060121: Swift XRT refined analysis
  40. GRB 060121: Confirmation of Afterglow
  41. GRB060121: SARA Observations
  42. GRB 060121: optical observations
  43. GRB 060121: Infrared Observations
  44. GRB 060121: optical observations
  45. GRB 060121: Optical imaging
  46. GRB060121 - SDSS pre-burst observations
  47. GRB 060117: PROMPT Observations
  48. GRB060117 - ATCA 3/6cm radio limits - correction
  49. GRB060117 - ATCA 3/6cm radio limits
  50. GRB 060116: photometric redshift - the farthest GRB?
  51. GRB 060116: possible I-J dropout
  52. GRB 060116: UKIRT IR Observations
  53. GRB 060116: PROMPT Observations
  54. GRB 060117: nearby galaxy
  55. GRB 060116: VLT optical observations
  56. GRB 060115: PROMPT Observations
  57. GRB 060116: IR Candidate Afterglow
  58. GRB060115: REM observations
  59. GRB 060116 : Lulin optical limit
  60. GRB060116: Faulkes North observation
  61. GRB 060115: absorption redshift
  62. GRB 060114: REM observations
  63. GRB 060114: Swift/UVOT Observations
  64. GRB 060114: Swift XRT upper limit
  65. GRB060114: Faulkes North observation
  66. GRB 060108: IR observations of afterglow
  67. GRB 060108: Evidence for an XRT Position Offset
  68. GRB 060110: KAIT observations
  69. GRB060111A: RTT150 optical observations
  70. GRB 060110: MARGE observations
  71. GRB 060111(a): P60 Observations
  72. GRB 060111B: Gualba observatory limit
  73. GRB 060108: VLT K-band observations
  74. GRB 060111: TAROT optical observation
  75. GRB060111 : XRT refined analysis
  76. GRB 060110: Mitsume optical observations
  77. GRB 060110: UKIRT K-band observations
  78. GRB 060110: IR Candidate Afterglow
  79. GRB 060110: Super-LOTIS observations
  80. GRB 060110: Correction
  81. GRB 050110: IR Observations
  82. GRB 060108: ISAS early observations and near IR upper limit
  83. GRB060108: P200 Ks Observations
  84. GRB 060108: early UKIRT K-band observations
  85. GRB 060108: a dark burst?
  86. GRB 060108: VLT J-band observations
  87. GRB 060108: Mitsume optical observations
  88. GRB060108: SDSS pre-burst observations
  89. GRB060108: Faulkes Telescope observation
  90. GRB 060105: Radio observations
  91. GRB 060105: ISAS observations and near IR upper limit
  92. GRB 060105: Mitsume optical observations
  93. GRB 060102 - no XRT afterglow
  94. GRB051211B: optical observations
  95. GRB051227: SARA Observations
  96. GRB 051221B: Optical Observations with Kuiper 1.54m
  97. GRB 051227: optical observation
  98. GRB051221B: Radio observations
  99. GRB 051221A: VLA Radio Observations
  100. GRB051227: Radio Observations

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