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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"

20951 results found.

  1. GRB 140110A Tiled Swift observations
  2. GRB 140105A: MASTER-Net early optical observations and time correction
  3. GRB 131231A: AAO optical observations
  4. GRB 140108A: Swift/UVOT Detection
  5. GRB 140108A: theoretical prediction of redshift and of supernova occurrence
  6. GRB 140108A: Mondy optical observations
  7. GRB 140108A: 1.23m CAHA observations
  8. New Fermi-LAT GRB Table
  9. GRB 140105A: HCT Observations
  10. GRB 140105A: continued iPTF observations and rejection of optical candidates
  11. GRB 140105A: Swift XRT observations
  12. GRB 140105A/Fermi410578384: MASTER-Net early optical observations
  13. GRB 140104B: Swift XRT observations
  14. GRB 140102A: Swift/UVOT Detection
  15. Fermi410578384: iPTF optical afterglow candidates for a possible short GRB
  16. GRB 140102A: BOOTES-4 early optical observations
  17. GRB 131209A: Further Swift XRT observations
  18. GRB 140103A: Lulin Optical r-band Observations
  19. GRB 131231A : Lulin Optical Observations
  20. GRB140104A : Xinglong TNT observation. A bright star is located nearby
  21. GRB 140102A, Optical Observations
  22. GRB 131231A, Optical Observations
  23. GRB 140103A: P60 Observations
  24. GRB 140102A: P60 observations
  25. GRB 131231A: Swift/UVOT Observations of the Optical Afterglow
  26. GRB 140103A: Swift/UVOT Upper Limits
  27. GRB 140102A: Fermi/GBM Observation
  28. GRB 140103A: Swift-XRT refined analysis
  29. GRB 140102A: GROND observations
  30. GRB 140103A: MASTER-Net optical observations
  31. GRB 140102A: I-band observations from IAC80 and 1.23m CAHA telescopes
  32. GRB 140102A: Early optical observations from Nanshan
  33. GRB 131231A: Gemini-South Redshift
  34. GRB 131231A: P60 observations
  35. GRB 131231A: Swift-XRT observations
  36. GRB 131231A: Fermi GBM detection
  37. GRB 131231A: iPTF optical afterglow candidate coincident with Nanshan detection
  38. GRB 131231A: afterglow confirmation from the NOT
  39. GRB 131231A: Nanshan afterglow candidate
  40. GRB 131229A: CARMA 3mm observations
  41. GRB 131229A: Magellan upper limit
  42. GRB 131229A: GROND observations
  43. GRB 131229A: Swift/UVOT Upper Limits
  44. GRB 131227A: GROND Upper Limits
  45. GRB 131229A: KAIT Optical Upper Limit
  46. GRB 131229A: P60 nondetection
  47. GRB 131224A: 5.8 GHz VLA observations
  48. GRB 131227A: P60 Limits
  49. GRB 131227A: Gemini-North Redshift
  50. GRB 131227A: Xinglong optical observations
  51. GRB 131227A: Swift/UVOT Upper Limits
  52. GRB 131227A: OT candidate from KAIT Optical observations
  53. GRB 131224A: Swift/UVOT Upper Limits
  54. GRB 131225A: MASTER-Net optical observations
  55. GRB 131224A: Swift-XRT observation
  56. GRB 131224A: MASTER-Net early optical observations
  57. GRB 131218A: GROND Upper Limits
  58. GRB 131218A: Swift XRT and UVOT observations
  59. GRB 131218A: Zadko observatory - Gingin optical candidate
  60. GRB 131218A: TAROT La Silla observatory optical observations
  61. GRB 131205A: GROND confirmation of afterglow
  62. GRB 131209A: Swift XRT and UVOT observations
  63. GRB 131209A Tiled Swift observations
  64. GRB131202A : GROND observations
  65. GRB131205A : GROND Observations
  66. GRB 131205A: Swift/UVOT Upper Limits
  67. GRB 131205A: Zadko observatory - Gingin optical observations
  68. GRB 131202A: theoretical estimation of the redshift
  69. GRB 131127B: rejection of optical counterpart candidates
  70. GRB 090530: X-shooter redshift
  71. GRB 131127A: optically dark burst
  72. GRB 131202A: Swift/UVOT Upper Limits
  73. GRB 131202A: RATIR Optical and NIR Observations
  74. GRB 131202A: Bassano Bresciano Observatory optical upper limit
  75. GRB 131202A: Tautenburg observations
  76. GRB 060614: theoretical derivation of the redshift and need for deeper search of the host galaxy
  77. GRB 131127B: Bassano Bresciano Observatory optical observations of iPTF13ecv
  78. GRB 131128A: Bassano Bresciano Observatory optical upper limit
  79. GRB 131127A: RATIR Rejection of High-z Candidate
  80. GRB 131125A: MASTER-Net very early optical observations
  81. GRB 131128A: GROND observations of the afterglow
  82. GRB 131128A: Swift/UVOT Detection
  83. GRB 131127B: Bassano Bresciano Observatory optical observations
  84. GRB 131128A: T100 observations
  85. GRB 131128A: Nanshan afterglow confirmation
  86. GRB 131128A: MASTER-Net optical observations
  87. GRB 131128A: Nanshan afterglow candidate
  88. GRB 131127B: MASTER-Net optical observations
  89. GRB 131127A: Bassano Bresciano Observatory optical upper limit
  90. GRB 131127B: Nanshan optical observations
  91. GRB 131127A: Swift/UVOT Upper Limits
  92. GRB 131127A: RATIR Optical and NIR Observations, High-z Candidate
  93. Fermi407254341: iPTF optical afterglow candidates
  94. GRB 131127A. 1.5m OSN optical limit
  95. GRB 131127A: Nanshan optical upper limit
  96. GRB 131127A: MASTER-NET optical observations
  97. GRB 131122A: Swift/UVOT Upper Limits
  98. GRB 131122A: Swift-XRT observations
  99. GRB 131122A: i-band observations from NOT
  100. GRB 131122A (INTEGRAL trigger N6392): MASTER-NET optical observation

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