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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"

20966 results found.

  1. Fermi403206457: continued P60 observations and fading behavior
  2. Fermi403206457: NOT optical observations
  3. Fermi403206457: iPTF detection of a possible optical afterglow
  4. Trigger 574266 is not a Swift detection of a known source
  5. GRB 130925A: Possible signatures of binary nature in the afterglow - Request for observations
  6. GRB 130831A: Continued RATIR Optical and NIR Observations
  7. GRB 131004A: Skynet PROMPT/DSO-14 upper limits
  8. GRB 131004A: CARMA 93 GHz upper limit
  9. GRB 131004A: Swift/UVOT Detection
  10. GRB 131004A: RATIR Optical and NIR Upper Limits
  11. GRB 131004A: GROND observations of the afterglow
  12. GRB131004A: Magellan Redshift
  13. GRB 131004A: Liverpool Telescope optical afterglow observations
  14. GRB 130925A: 3mm observations with CARMA
  15. GRB 130925A/Sw J0244-2609: mm observations at PdBI
  16. GRB 131002B: GROND upper limits
  17. GRB 131002B: Swift/UVOT Upper Limits
  18. GRB 131002A: Swift/UVOT Detection
  19. GRB 131002A: ISON-NM optical observations
  20. GRB 131001A: Swift UVOT and XRT Upper Limits
  21. NuSTAR observations of GRB 130925A
  22. GRB 131001A detected in ground analysis of Swift-BAT data
  23. GRB 130925A: continuing Swift/XRT monitoring
  24. IPN Observations of GRB 130925A
  25. GRB 130929A: Swift/UVOT Upper Limits
  26. GRB 130831A: Continued RATIR Optical and NIR Observations
  27. GRB 130929A: TAROT La Silla observatory optical observations
  28. GRB 130925A: Swift/UVOT Upper Limits
  29. GRB 130925A: sub-mm non-detection with SMA
  30. GRB 130925A: Continued RATIR Optical and NIR Observations
  31. GRB 130925A: RATIR Optical and NIR Observations
  32. GRB 130925A: Swift-XRT refined Analysis
  33. GRB 130925A: Initial Similarities to Swift J1644+57
  34. GRB 130925A: TAROT La Silla observatory optical observations
  35. GRB 130925A: VLT/X-shooter redshift
  36. GRB 130925A: VLT/UVES observations
  37. GRB 130831A: RTT150 optical observations
  38. GRB 130702A: RTT150 optical observations
  39. GRB 130903A: optical observations
  40. GRB 130907A: Maidanak optical observations
  41. Fermi Trigger 401326696: MASTER prompt optical observations
  42. GRB 130831A: Maidanak optical observations, possible emerging Supernova
  43. GRB 130919A: Skynet PROMPT-CTIO optical upper limits
  44. GRB 130903A: Further Swift XRT observations.
  45. GRB 130606A: Chandra observation
  46. GRB 130912A: Swift/UVOT Upper Limits
  47. GRB 130912A: 5.8 GHz VLA upper limit
  48. GRB 130912A: RATIR Optical and NIR Upper Limits
  49. GRB 130912A: WHT confirmation of optical counterpart
  50. GRB 130907A: Continued RATIR Optical and NIR Observations
  51. GRB 130912A: P60 Observations
  52. GRB 130907A: MASTER refined analysis
  53. GRB 130912A: Skynet DSO-14/Yerkes-41/PROMPT-CTIO observations
  54. GRB 130912A: REM optical/NIR upper limits
  55. GRB 130912A: GROND observations
  56. GRB 130912A: KAIT optical upper limit
  57. GRB 130907A: AMI radio detection
  58. GRB 130907A: Continued RATIR Optical and NIR Observations
  59. GRB 130907A: RATIR Optical and NIR Observations
  60. GRB 130907A: WSRT radio detection
  61. GRB 130828A: Further Swift XRT observations
  62. GRB 130907A: T21 optical observations
  63. GRB 130907A: VLA detection
  64. GRB 130907A: Swift/UVOT Detection
  65. GRB 130907A: Early Tautenburg detections, red afterglow
  66. GRB 130907A: Skynet DSO-14/Yerkes-41/GORT confirmation of a fading afterglow
  67. GRB 130907A: RATIR Optical and NIR Afterglow Confirmation
  68. GRB 130907A: Skynet DSO-14/Yerkes-41 detections of a possible afterglow
  69. GRB 130831A: Maidanak optical observations
  70. GRB 130831A: ISON-Kislovodsk optical observations
  71. GRB 130831A: ISON-UAFO optical observations
  72. GRB 130907A: MASTER early OT observations
  73. Swift follow-up results of the possible weak INTEGRAL GRB
  74. GRB 130903A: Swift/UVOT Upper Limits
  75. GRB 130831A: RATIR Optical and NIR Upper Limits
  76. GRB 130822A: nearby galaxy redshifts
  77. GRB 130903A: GROND Afterglow Discovery
  78. GRB 130831A: JCMT SCUBA-2 sub-mm observation
  79. GRB 130903A: Swift-XRT observations
  80. GRB 130903A: GROND Upper Limits
  81. GRB 130831A: Swift/UVOT Observations
  82. GRB 130831A: Optical Observations via Virtual Telescope, follow-up
  83. GRB 130831A: RATIR Optical and NIR Observations
  84. GRB 130831A: Continued Skynet/PROMPT-SSO, PROMPT-CTIO and Yerkes-41 detections
  85. GRB 130831A: VLA Observations
  86. GRB 130831A: T100 observations
  87. GRB 130831B: Swift/UVOT Upper Limits
  88. GRB 130831B: GROND upper limits
  89. GRB 130831A: optical observations
  90. GRB 130831A: Optical Observations via Virtual Telescope
  91. GRB 130831A: Montarrenti Observatory optical observations
  92. GRB 130831A: Skynet/PROMPT-SSO detections
  93. GRB 130831A: Weihai optical observations
  94. GRB 130829A: AAO optical observations
  95. GRB 130828A: Swift XRT and UVOT observations
  96. GRB 130829A: NOT optical observations
  97. GRB 130828A Tiled Swift observations
  98. GRB 130822A: 5.8 GHz VLA upper limit
  99. GRB 130822A: Gemini Observations
  100. GRB 130822A: WHT ACAM observations

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