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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"

16159 results found.

  1. GRB 060223A:Xinglong optical limits
  2. GRB 060223B: ART optical limits
  3. GRB 060218: rebrightening
  4. Correction to GCN 4816 on GRB060218
  5. GRB 060218/SN 2006aj: optical observations
  6. GRB060218: Optical brightening in V and R
  7. GRB 060223: Keck redshift
  8. GRB 060223: Swift/UVOT Confirmation of Optical Afterglow
  9. Spectral properties of GRB060218/SN2006aj
  10. GRB 060218: rebrightening
  11. GRB 060218: emergence of the underlying SN spectrum
  12. GRB 060218: Decline in r-band flux
  13. GRB 060218: spectroscopic observations
  14. GRB060218: Optical Spectroscopy of GRB-SN
  15. GRB060218: VLT spectroscopy
  16. GRB 060218: Optical Observations at Xinglong Obs.
  17. GRB060218: UV Detection and Light Curves
  18. GRB060218: Radio Afterglow Discovery
  19. GRB 060218: MDM Redshift
  20. GRB 060218: optical/nIR observations at La Palma
  21. Oddball GRB 060218, transient or GRB?
  22. Brightening of the Optical Counterpart of the Possible GRB 060218
  23. GRB 060218: MDM Observations
  24. GRB 060218A: ROTSE-III Possible Optical Flare
  25. Further UVOT Observations of the Candidate Optical Afterglow for GRB 060218
  26. GRB 060213: optical afterglow not confirmed
  27. Swift UVOT observations of GRB060213
  28. GRB 060213: optical afterglow candidate
  29. GRB 060206: Confirmation of Rapid Fading at Optical Wavelengths
  30. GRB 060211b: WIRO NIR Observations
  31. GRB060213:_MASTER_optical_observation
  32. GRB060206: Swift XRT observations of an unbroken powerlaw decay
  33. GRB 060210: Radio Observations
  34. GRB 060211a: WIRO NIR Observations
  35. GRB060211B: REM optical and NIR observations
  36. GRB060121: optical observations
  37. GRB060110: optical observations
  38. GRB060105: optical observations
  39. GRB 060210: ARC NIR Detection of Afterglow and Possible Host Galaxy
  40. GRB 060206: SOAR Detections
  41. GRB 050826: Optical Afterglow and Host Galaxy
  42. GRB060211b: optical observation
  43. GRB 060210: Optical Observations
  44. GRB060211: Faulkes North observation
  45. GRB 060211: ROTSE-III Optical Limits
  46. GRB060210: Swift XRT Refined Analysis
  47. GRB060206, optical observations
  48. GRB 060210 : Xinglong and Lulin optical limit
  49. GRB060210: Optical Observations
  50. GRB060210: Gemini absorption spectroscopy
  51. GRB060210: Early Optical Observations
  52. GRB 060210: optical evolution
  53. GRB060210: Optical afterglow
  54. GRB060209: RTT150 optical observations
  55. GRB 060209 : TAROT optical observation
  56. GRB060209A: MASTER optical observation
  57. GRB 060206: WSRT Radio Observations
  58. GRB 060206: More PROMPT Detections
  59. GRB 060121 : WIDGET Pre-trigger limit
  60. GRB 060206: optical observations at Asiago
  61. Orphan GRB Afterglow candidate
  62. GRB 060206: Subaru/FOCAS optical spectroscopy
  63. GRB 060206: Super-LOTIS observations
  64. GRB060204A: Swift/UVOT observations
  65. GRB 060206 : Lulin optical observations
  66. GRB060206: Swift XRT Refined Analysis
  67. GRB060206: Liverpool Telescope observation
  68. GRB060206: P60 Optical Observations
  69. GRB060206: Swift XRT Position
  70. GRB 060206: RAPTOR observations of afterglow candidate variability.
  71. GRB 060206: High redshift burst
  72. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  73. GRB060206: Optical afterglow
  74. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  75. GRB060203: WHT Z-band observations
  76. GRB060204C: optical observation
  77. GRB 060204B: BVRi-band detections of optical afterglow
  78. GRB 060204A: FRAM optical observations
  79. GRB 060204C: optical observations
  80. GRB 060204B: ART early limit
  81. GRB060204B: Swift XRT Team Refined Analysis
  82. GRB 060204C: BOOTES-IR optical limits
  83. GRB 060204C: Liverpool Telescopes optical limit
  84. GRB 060204C: ROTSE-III Optical Limits
  85. GRB 060124: Radio Observations
  86. GRB 060204B: ART optical limit
  87. GRB060204B, optical observation
  88. GRB 060203: RTT150 optical observations
  89. GRB060203: Swift XRT Team Refined Analysis
  90. GRB060203 - Swift UVOT observation
  91. GRB 060203: P60 Confirmation of Optical Afterglow
  92. Possible GRB 060203: candidate optical counterpart
  93. Possible GRB 060203: optical observations at Asiago
  94. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  95. GRB060202, optical observation
  96. GRB060202: Faulkes North observation
  97. GRB 051211A: MDM Observations
  98. GRB060130: Optical imaging
  99. GRB 060130, SMARTS optical observations
  100. GRB 060130: FRAM optical observations

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