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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"

20950 results found.

  1. GRB 140928A: LCO-Cerro Tololo observations
  2. GRB 140928A: GROND Afterglow Candidate
  3. GRB 140928A: Swift-XRT observations
  4. GRB 140927A: Swift-UVOT analysis
  5. GRB 140919A: Swift/UVOT Detection
  6. GRB 140919A: GROND afterglow candidate
  7. GRB 140919A: Swift/UVOT observations
  8. GRB 140919A: Swift-XRT observations
  9. GRB 140916B: LOT and iPTF follow-up of optical afterglow candidates
  10. Swift detection of outburst from 4U 1700+24
  11. GRB 140916A: Swift/UVOT Upper Limits
  12. GRB 140916A: UKIRT J-band observations
  13. GRB 140916B: iPTF Optical Observations
  14. GRB 140916A: FTS observations
  15. GRB 140907A: Continued DCT Observations
  16. Possible radio detection of GRB 140903A with the GMRT
  17. GRB 140907A: Mondy optical observations
  18. GRB 140903A: Chandra detection of the afterglow
  19. GRB 140909A: Swift/UVOT Upper Limits
  20. GRB 140909A: Swift-XRT observations
  21. GRB 140907A: 1.23m CAHA optical observations
  22. GRB 140907A: TShAO observations
  23. GRB 140907A: MASTER optical observations
  24. GRB 140907A: Nishi-Harima NIR Observations
  25. GRB 140907A: Discovery Channel Telescope observations
  26. GRB 140907A: T100 observations
  27. GRB 140907A: redshift from the 10.4m GTC telescope
  28. GRB 140907A : Virtual Telescope optical observations
  29. GRB140907A: Swift UVOT detection
  30. GRB 140907A : Optical observations from Nanshan
  31. GRB 140906A - Fermi GBM Detection
  32. GRB 140906A: iPTF optical transient candidates
  33. GRB 140903A: Possible optical variability
  34. GRB 140903A: NOT optical and NIR observations
  35. GRB 140901B: Swift XRT observation
  36. GRB 140903A: FTN observations
  37. GRB 140903A: ISON-Kislovodsk observations
  38. GRB 140903A: 6 GHz VLA detection
  39. GRB 140903A: tentative spectroscopic redshift
  40. GRB 140903A: Swift/UVOT Upper Limits
  41. GRB 140903A: P60 Optical Observations
  42. GRB140903A: Discovery Channel Telescope Optical Detection
  43. GRB 140831A: iPTF observations of a possible short burst detected by Fermi GBM
  44. GRB 140829A: iPTF optical observations
  45. IPN Triangulation of GRB 140824B
  46. GRB 140818B: TLS observations
  47. GRB 140824B: Swift observations
  48. Fermi TRIGGER_NUM 430645968: MASTER OT inside error box
  49. Swift Mission Operations Center Moving Tomorrow
  50. Fermi TRIGGER_NUM 430583595: MASTER OT 20 hours later
  51. Fermi TRIGGER_NUM 430583595: MASTER OT JR011101.13+603337.5 detection
  52. GRB 140824A: OSN optical limit
  53. GRB 140824A: Swift/UVOT Upper Limits
  54. GRB 140817A: NOT optical observations
  55. Fermi GBM Trigger 140819576/ 430148973/ MASTER OT
  56. Fermi trigger 430148973: Swift-XRT observation
  57. GRB 140818A: GROND confirmation of afterglow candidate
  58. GRB 140808A/iPTF14eag: AMI 15 GHz detection
  59. GRB140819A: Deep GROND Upper Limits
  60. Fermi 430148973/MASTER candidate: LCO-Sutherland observations
  61. Fermi trigg_num 430148973: OSN I-band observations
  62. GRB 140818B: Swift/UVOT Upper Limits
  63. Radio upper limit on the GRB 140808A with the GMRT
  64. GRB140818B : GROND afterglow candidate
  65. GRB 140818B: OSN I-band afterglow candidate
  66. GRB 140817A: Swift/UVOT Afterglow Detection
  67. Swift detection of SAX J1712.6-3739
  68. GRB 140818A: Swift-XRT and UVOT potential afterglow detection
  69. GRB 140818A Tiled Swift observations
  70. GRB 140808A / PTFeag: VLA K-band observations
  71. GRB 140815A: GROND afterglow candidate
  72. GRB 140815A: Swift-XRT observations
  73. GRB 140814A: Swift-XRT and UVOT observations
  74. GRB 140814A: MASTER optical follow-up inspection
  75. GRB 140814A: Swift-XRT and UVOT observations
  76. Swift Mission Operations Center Moving
  77. Swift trigger 609139 is probably 4U 1850-03
  78. Swift observations of possible GRB 140809A candidate
  79. GRB 140809A : Virtual Telescope optical observations
  80. GRB 140809A (FERMI trigger 429246673): MASTER follow-up inspection
  81. GRB 140808A: Swift/UVOT Upper Limits
  82. GRB 140808A: Redshift from the 10.4m GTC telescope
  83. GRB 140808A: Swift-XRT observations
  84. GRB 140808A: optical afterglow candidate iPTF14eag
  85. GRB 140801A: AAO optical observations
  86. GRB 140801A: GROND Afterglow detection, unbroken decay
  87. GRB140801A: Swift/XRT further observations
  88. GRB 140730A: GROND Upper limits
  89. GRB 140801A: BTA confirmation of redshift
  90. GRB 140801A: Swift-XRT observations
  91. GRB 140801A : Virtual Telescope optical observations
  92. GRB 140801A: Redshift from the 10.4m GTC telescope
  93. GRB 140801A: NOT afterglow confirmation
  94. GRB 140730A: LCO-Sutherland observations
  95. GRB 140730A: Swift/UVOT Upper Limits
  96. Radio upper limit on the GRB 140713A with the GMRT
  97. GRB 140729A: iPTF optical upper limit
  98. Swift Trigger 607506 is probably noise
  99. GRB 140729A: Swift-XRT and UVOT observations
  100. GRB 140729A Tiled Swift observations

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