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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"

8294 results found.

  1. GRB 080303: REM NIR afterglow candidate
  2. GRB 080229: VLT NIR observations
  3. GRB 080229: TNG NIR observations
  4. GRB 080229: REM NIR observations
  5. GRB 080229: Faulkes Telescope South optical limit
  6. GRB 080229: Swift detection of a bright burst
  7. GRB 080218B: REM NIR early upper limits
  8. GRB 080218B: Swift detection of a burst
  9. GRB080212: Optical afterglow candidate observed by MITSuME Telescope
  10. GRB 080212: Swift detection of a burst
  11. GRB 080207: VLT NIR early upper limits
  12. GRB 080210: VLT redshift
  13. GRB 080210: Swift detection of a burst with optical afterglow
  14. GRB 080210: TAROT La Silla observatory optical detection
  15. GRB080207: RTT150 Optical Observations
  16. GRB 080207: REM NIR observations
  17. GRB 080207: Swift detection of a burst
  18. GRB 080205: Swift detection of a burst
  19. GRB 080130: REM NIR observations
  20. GRB 080129: KAIT optical limits
  21. GRB 080129: Gemini-South photometry
  22. GRB 080129: Gemini-South Imaging Observations
  23. GRB 080129 (?): UVOT Upper Limits
  24. GRB 080121: Upper limit on X-ray afterglow
  25. GRB 080123, Swift-BAT refined analysis
  26. GRB 080123: Swift detection of a short burst
  27. XRF 080109 / SN 2008D: 1.4 GHz WSRT Radio Observations
  28. XRF 080109 / SN 2008D: WSRT Radio Detection
  29. Opticall follow-ups for the X-ray transient in NGC 2770
  30. Bright X-ray Transient in NGC 2770 - A low-luminosity XRF?
  31. GRB 071227: optical afterglow
  32. GRB 071227: Magellan redshift confirmation
  33. GRB 071227: VLT probable redshift of the candidate host galaxy
  34. GRB071227: Swift/UVOT refined analysis
  35. GRB 071227: REM NIR and Optical observations
  36. GRB 071227: Swift detection of a burst
  37. GRB 070429B: Possible UVOT Detection of an Optical Afterglow
  38. Disregard the "GRB 071126" position
  39. GRB071104: NIR Afterglow Candidate at TNG
  40. GRB 071122: MASTER optical observation
  41. GRB 071122: Corrected P60 Coordinates
  42. GRB 071122: P60 Optical Afterglow Candidate
  43. GRB 071122: Swift detection of a burst
  44. Konus-Wind and Konus-A observations of GRB 071117
  45. GRB 071117: TAROT La Silla observatory optical observations
  46. GRB 071118: Swift detection of a burst
  47. GRB 071117, Swift-BAT refined analysis
  48. GRB 071117: Initial Swift/UVOT observations
  49. Swift detection of MXB 0656-072
  50. GRB 071112C: WSRT Radio Observations
  51. GRB 071112B: Gemini Optical Imaging
  52. GRB 071112C: Swift detection of a burst with an optical counterpart
  53. GRB 071112: Swift detection of a possible burst
  54. GRB071109: Super-LOTIS observations
  55. GRB 071109: further Swift-XRT analysis
  56. GRB 071104: Possible Swift UVOT Afterglow Candidate
  57. GRB071101: Optical and NIR upper limits by KANATA
  58. GRB 071101: Swift detection of a burst
  59. GRB 071031: REM NIR and Optical observation
  60. GRB 071031: Swift detection of a burst with an optical counterpart
  61. GRB 071028: SARA observations of variable source
  62. GRB 071028, Swift-BAT refined analysis
  63. GRB 071028: Swift detection of a burst
  64. GRB 071003: Infrared Photometry with Keck Adaptive Optics
  65. GRB 071025: Swift detection of a burst
  66. GRB 071021: R-band detection and analysis
  67. GRB071021: Optical+NIR observations
  68. GRB 071021: Subaru NIR observation
  69. GRB 071021: retraction of Faulkes Telescope South candidate
  70. GRB 071021: Swift-XRT Team refined analysis
  71. GRB 071021 : Lulin R-band limit
  72. GRB 071021: Faulkes Telescope South optical candidate
  73. GRB 071018: SARA observations
  74. GRB 071010B: Suzaku WAM observation of the prompt emission
  75. GRB 071013: 3rd TLS Epoch - constraints on variability
  76. GRB 071013: TLS 2nd epoch - Kornienko candidate constant
  77. GRB 071013: Optical observations
  78. GRB 071013: optical observations at NOT
  79. GRB071013: optical limit
  80. GRB 071011, Optical afterglow
  81. GRB 071011: Confirmation of P60 optical afterglow
  82. GRB 071011: P60 Optical Afterglow Candidate
  83. GRB 071011: MARGE Optical Limits
  84. GRB 071011: XRT afterglow detection
  85. GRB 071011: Early Super-LOTIS Observations
  86. GRB 071011: Optical afterglow candidate
  87. Optical Observation: GRB 071010
  88. Optical observations: GRB 071010A
  89. GRB 071010 REM NIR observations
  90. GRB 071003: VLT spectroscopy
  91. GRB 071003 Optical observations
  92. GRB 071003: P60 Confirmation of Optical Afterglow
  93. GRB 070920B: NOT optical observations
  94. GRB070917: Confirmation of optical afterglow
  95. Swift Status and XRT Calibration Uncertainties
  96. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  97. GRB 070913: Afterglow candidate detected by TAROT La Silla observatory
  98. IPN search for a GRB associated with TAROT transient on August 31
  99. Intense burst from SGR 1806-20 detected on September 7
  100. GRB 070809: Confirmation of optical transient

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