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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"

20960 results found.

  1. GRB060204B - SDSS pre-burst observations
  2. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  3. GRB 060203: RTT150 optical observations
  4. GRB 060203: IR Counterpart
  5. GRB060203: Observations with SARA
  6. GRB 060203: P60 Confirmation of Optical Afterglow
  7. Possible GRB 060203: candidate optical counterpart
  8. Possible GRB 060203: optical observations at Asiago
  9. GRB 060202: PROMPT Observations
  10. GRB 060202: Gemini-N J, H, K_s observations
  11. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  12. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  13. GRB 060202: Refined analysis of the Swift-BAT burst
  14. GRB 060121: Gemini Late-time Observations
  15. Erratum: SDSS pre-burst observations of GRB fields
  16. GRB 060130: PROMPT Observations
  17. GRB 051211A: MDM Observations
  18. GRB 060123: VLA Radio Observations
  19. GRB060130: REM infrared observations
  20. GRB 060130, SMARTS optical observations
  21. GRB 060130: FRAM optical observations
  22. Possible GRB 051221B: MDM Correction
  23. GRB 060121: Confirmation of NIR Afterglow
  24. GRB060124: optical observations
  25. GRB 060123: Swift refined analysis of an unusual GRB
  26. GRB060124 optical observations
  27. GRB 060121: Probable Detection of NIR Afterglow
  28. GRB 060116 HST observations
  29. GRB 060124 Optical Observations
  30. GRB 060124: ART optical limits during the burst
  31. GRB 060123: P200 Observations
  32. GRB 060124: Keck optical spectrum
  33. GRB 060124: MDM Optical Spectrum
  34. GRB 060124: R band Observations
  35. GRB060124: optical observations at Asiago
  36. GRB060123: SDSS pre-burst observations
  37. GRB 060124: Optical Observations at Tautenburg
  38. GRB 060116: Radio Detection
  39. GRB 060116: MARGE optical observations
  40. GRB 060121: Liverpool Telescopes optical limits
  41. GRB 060121: Swift XRT refined analysis
  42. GRB 060121: Confirmation of Afterglow
  43. GRB060121: SARA Observations
  44. GRB 060121: optical observations
  45. GRB 060121: Infrared Observations
  46. GRB 060121: optical observations
  47. GRB 060121: Optical imaging
  48. GRB060121 - SDSS pre-burst observations
  49. GRB 060117: PROMPT Observations
  50. GRB060117 - ATCA 3/6cm radio limits - correction
  51. GRB060117 - ATCA 3/6cm radio limits
  52. GRB 060116: photometric redshift - the farthest GRB?
  53. GRB 060116: possible I-J dropout
  54. GRB 060116: UKIRT IR Observations
  55. GRB 060116: PROMPT Observations
  56. GRB 060117: nearby galaxy
  57. GRB 060116: VLT optical observations
  58. GRB 060115: PROMPT Observations
  59. GRB 060116: IR Candidate Afterglow
  60. GRB060115: REM observations
  61. GRB 060116 : Lulin optical limit
  62. GRB060116: Faulkes North observation
  63. GRB 060115: absorption redshift
  64. GRB 060114: REM observations
  65. GRB 060114: Swift/UVOT Observations
  66. GRB 060114: Swift XRT upper limit
  67. GRB060114: Faulkes North observation
  68. GRB 060108: IR observations of afterglow
  69. GRB 060108: Evidence for an XRT Position Offset
  70. GRB 060110: KAIT observations
  71. GRB060111A: RTT150 optical observations
  72. GRB 060110: MARGE observations
  73. GRB 060111(a): P60 Observations
  74. GRB 060111B: Gualba observatory limit
  75. GRB 060108: VLT K-band observations
  76. GRB 060111: TAROT optical observation
  77. GRB060111 : XRT refined analysis
  78. GRB 060110: Mitsume optical observations
  79. GRB 060110: UKIRT K-band observations
  80. GRB 060110: IR Candidate Afterglow
  81. GRB 060110: Super-LOTIS observations
  82. GRB 060110: Correction
  83. GRB 050110: IR Observations
  84. GRB 060108: ISAS early observations and near IR upper limit
  85. GRB060108: P200 Ks Observations
  86. GRB 060108: early UKIRT K-band observations
  87. GRB 060108: a dark burst?
  88. GRB 060108: VLT J-band observations
  89. GRB 060108: Mitsume optical observations
  90. GRB060108: SDSS pre-burst observations
  91. GRB060108: Faulkes Telescope observation
  92. GRB 060105: Radio observations
  93. GRB 060105: ISAS observations and near IR upper limit
  94. GRB 060105: Mitsume optical observations
  95. GRB 060102 - no XRT afterglow
  96. GRB051211B: optical observations
  97. GRB051227: SARA Observations
  98. GRB 051221B: Optical Observations with Kuiper 1.54m
  99. GRB 051227: optical observation
  100. GRB051221B: Radio observations

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