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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"

32494 results found.

  1. GRB 050315, SMARTS optical/IR afterglow observations
  2. GRB 050315 I-band observations
  3. GRB050315: Radio afterglow
  4. GRB 050315: Absorption redshift
  5. GRB 050315: Optical afterglow identification
  6. GRB050315: Swift-BAT Refined analysis
  7. Non-detection of GRB050315 in ATCA Radio Observations
  8. GRB 050315: Swift XRT Position
  9. GRB 050219b: Gemini/GNIRS near-infrared spectroscopy
  10. GRB 050315: Early Observations with Swift/UVOT
  11. GRB050223: No XMM-Newton OM detection of afterglow emission
  12. GRB 050306: Radio Observations
  13. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  14. GRB 050306: optical afterglow
  15. Swift-BAT trigger 107873: No Swift XRT counterpart
  16. GRB 050306: Confirmation of X-ray afterglow
  17. GRB 050309, Early optical limits from RAPTOR
  18. GRB050309: Early optical limit from P60
  19. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  20. GRB 050306: CORRECTION to date of observation
  21. GRB 050306: R-band observations
  22. GRB 050306: No Swift UVOT Optical Counterpart Detected
  23. GRB 050306: REM optical-infrared observations
  24. GRB 050306: Possible X-ray Afterglow Position from the Swift
  25. GRB 050306,optical observation
  26. GRB050215B: Late-Time Swift UVOT Observations
  27. PROMPT VRcIc Observations of GRB 050223
  28. XRF/GRB 050215B: Radio Observations
  29. GRB 050219b: candidate NIR afterglow
  30. GRB 050223: optical observations
  31. GRB050223 XMM-Newton observation
  32. INTEGRAL detection of GRB 050223
  33. GRB050223: No Swift UVOT Detection of Afterglow Emission
  34. GRB050223: ROTSE-III Optical Observations
  35. GRB050219b: CORRECTION to time of UVOT observations
  36. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  37. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  38. GRB 050219b: CORRECTION to refined XRT position
  39. GRB 050219a: Optical observations from LCO
  40. GRB 050219b: Optical and near-IR observations from LCO
  41. GRB050219b: No Swift UVOT Detection of Afterglow Emission
  42. GRB 050219b: CORRECTION: Swift XRT Position
  43. GRB 050219a, optical observations
  44. GRB 050219a: Refined XRT position
  45. GRB050219a: No Swift UVOT Detection of Afterglow Emission
  46. GRB 050219: Swift-BAT detection of a burst
  47. GRB050215b: Swift UVOT Detection of Afterglow Emission
  48. GRB 050215B: Radio Observations
  49. GRB 050215b: XRT confirmation of IR afterglow candidate
  50. GRB050215b: P60 Optical Observations
  51. GRB 050215b: Swift XRT Source Variability
  52. GRB 050215B: candidate afterglow
  53. GRB 050215b : Lulin follow-up observation
  54. GRB 050215b, BOOTES-2 simultaneous optical observations
  55. GRB 050215B: UKIRT K-band imaging
  56. GRB050215b: No Swift UVOT Detection of Afterglow Emission
  57. GRB050215a: No Swift UVOT Detection of Afterglow Emission
  58. GRB 050215b, BOOTES-1B optical limit
  59. GRB050215A: ROTSE-III Optical Observations
  60. GRB050209: TAROT optical observations
  61. short/hard GRB 050202, optical observations
  62. GRB050209: REM optical observations
  63. GRB 050209 I-band observation
  64. GRB050209: P60 Optical Observations
  65. GRB050209 (=U11568): A Long GRB Detected by HETE
  66. GRB 050128: Radio observations
  67. Further analysis of the short Swift-BAT GRB 050202
  68. GRB 050202: Second epoch radio observations
  69. GRB 050129: Optical observations
  70. GRB050202: Radio Observations
  71. GRB 050202: Optical observations with LCO40
  72. GRB 050128 Optical observation with REM
  73. GRB050128: Faulkes Telescope South observations
  74. GRB 050124: Radio Observations
  75. GRB 050128: near-infrared observations with REM
  76. GRB050128,optical observations
  77. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  78. GRB 050126: Radio Observations
  79. GRB050128 Swift-BAT observations
  80. GRB 050128: Swift XRT prompt afterglow position
  81. GRB 050124: K-band afterglow observations
  82. GRB050126: MASTER optical limit for KECK OT
  83. GRB050126: Burst Parameters Measured by BAT
  84. GRB050126: MASTER optical observations
  85. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  86. GRB 050124: NIR afterglow confirmed with Keck/NIRC
  87. GRB050124: No Swift UVOT Detection of Afterglow Emission
  88. GRB 050124, SMARTS optical/IR observations
  89. GRB 050117a: Radio Observations
  90. GRB 050124 I-band observation
  91. GRB 050124: NIR Candidates from Keck/NIRC
  92. GRB050124,optical observation
  93. GRB 050124 : Lulin R-band follow-up observation
  94. GRB 050124: Swift XRT Detection of X-ray Afterglow Emission
  95. GRB050124: Refined BAT position, spectral and fluence information
  96. GRB 050123 : I-band follow-up observation
  97. GRB050123: optical limit 1.8h before GRB
  98. GRB 050123: KAIT observations
  99. GRB050123: P60 Observations
  100. CFHTLS optical transient unlikely to be a GRB

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