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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"

20982 results found.

  1. GRB 070125: UVOT Observations of a Fading Optical Afterglow
  2. GRB 070125: Xinglong TNT optical observations
  3. GRB 070125: Continued P60 Observations
  4. GRB070125: Swift-XRT Refined Analysis
  5. GRB 070125: SARA detection in R
  6. GRB 070110: optical break
  7. Swift-BAT trigger 257213 is a Galactic Center transient
  8. GRB 070110: Continued Detection and Request for Ground Followup
  9. GRB 050904: Second Epoch of HST/NICMOS Observations
  10. GRB 070110 declared a "Burst of Interest" by Swift team
  11. GRB 070110: VLT absorption redshift
  12. GRB 070110: UVOT Observations of a Candidate Afterglow
  13. GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
  14. GRB070103: APO SPIcam i' and z' limits
  15. GRB 061201: Nearby Galaxy Cluster Abell 995 is at z=0.0865
  16. GRB070103: KPNO 4m+FLAMINGOS J limit
  17. GRB 070103: Swift/UVOT Upper limits
  18. GRB 070103: NOT observations
  19. GRB 070103: TAROT Calern observatory optical observations
  20. GRB061222a: optical observations
  21. erratum : SDSS Pre-burst Observations of GRB061126
  22. GRB 061210: Swift/XRT Astrometry Correction
  23. GRB 061222B: TAROT La Silla observatory early optical observations
  24. GRB 061218: TAROT La Silla observatory early optical observations
  25. GRB 061222A: Gemini Afterglow Candidate
  26. GRB061222B: Swift-XRT Refined Analysis
  27. GRB 061222B: BOOTES-IR optical observations
  28. GRB 061222A: Swift-XRT refined analysis
  29. GRB 061217: Magellan host galaxy redshift
  30. GRB 061222B: REM NIR/optical observations
  31. GRB 061222b, SMARTS optical/IR afterglow observations
  32. GRB 061222B: TAROT La Silla observatory optical observations
  33. GRB 061222b: Magellan redshift
  34. GRB 061222b: optical afterglow
  35. GRB 061201: Magellan redshift of nearby galaxy
  36. GRB 061217: Extended object in the revised XRT error circle
  37. GRB 061217 - Swift/XRT position correction
  38. GRB 061201: Magellan Redshift of nearby Abell cluster
  39. GRB 061218: TAROT La Silla observatory optical observations
  40. GRB 061217: TAROT Calern observatory optical observations
  41. GRB061217: VLT NIR observations
  42. GRB 061218, SMARTS optical/IR observations
  43. GRB 061218: REM prompt observations
  44. GRB 061217, SMARTS optical observations
  45. GRB 061217: optical observations at Calar Alto
  46. GRB 061217: Magellan Observations
  47. GRB 061217: REM prompt observations
  48. GRB 061210: MDM Follow-up Observation
  49. GRB061210: Swift/UVOT observations
  50. GRB 061210 : Faulkes North Telescope optical limit
  51. GRB 061213: MASTER-VWF-Kislovodsk observations
  52. GRB 061210: Gemini/GMOS Observations
  53. GRB 061126: Radio Observations
  54. GRB061210: Radio Observations
  55. GRB061201, VLT optical decay: correction
  56. GRB 061210: Swift-BAT detection of a short burst
  57. Optical Afterglow observations of GRB 061126
  58. GRB061126: optical observations
  59. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  60. GRB 061201: VLT optical decay
  61. GRB061126 : NMSU 1.0m observations
  62. GRB061202: optical/NIR observations with REM
  63. GRB 061201: VLT optical observations
  64. GRB 061201: Initial UVOT Observations
  65. GRB 061121, SMARTS optical/IR observations
  66. GRB 061121: flattening of the decay
  67. INT+WFC observations of GRB 061126
  68. GRB 061126: Possible Jet Break
  69. GRB 061121: Second Epoch ATCA Radio Observations
  70. GRB 061121: ATCA & WSRT Radio Observations
  71. GRB061121: optical observations
  72. GRB 061126: Early Super-LOTIS Observations
  73. GRB 061126: Tautenburg afterglow observations
  74. GRB061126: Optical afterglow observations from MIRO
  75. GRB061126: Optical afterglow observations from MIRO
  76. GRB 061126 : SDSS Pre-Burst Observations
  77. GRB 061126: Swift/UVOT Observations
  78. GRB 061126: SARA Observations
  79. GRB 061126: Early Detection of the IR Afterglow
  80. GRB 061126: Faulkes Telescope North Optical Observations
  81. GRB 061126: Swift detection of a burst
  82. GRB 061121: MDM Continued Monitoring
  83. GRB 061122: Confirmation of X-ray/Optical Afterglow
  84. GRB 061121: MDM Continuing Optical Decay
  85. GRB061121: optical observations
  86. GRB 061122: Candidate Optical Afterglow
  87. GRB061122: Swift/UVOT Optical Observations
  88. GRB061121: P60 Observations
  89. Radio detection of GRB 061121
  90. GRB 061121: MDM Optical Observations
  91. GRB 061121 declared "Burst of Interest" by Swift team
  92. Konus-Wind and Konus-A observations of GRB 061121
  93. GRB 061121: Swift/UVOT Observations
  94. GRB 061121: Optical observation at the KANATA 1.5m telescope
  95. GRB 061121: Faulkes Telescope North Optical Observation
  96. GRB061121: Keck spectroscopic observations
  97. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  98. GRB 060605: NIR Observations
  99. GRB 050915B: optical afterglow
  100. GRB 061110B: NIR Observations

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