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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"

20958 results found.

  1. GRB 140930B: Swift/UVOT Upper Limits
  2. GRB 140930B: MMT confirmation of the optical afterglow
  3. GRB 140930B: ISON-Kislovodsk observations
  4. GRB 140930B: WHT detection of candidate afterglow
  5. GRB 140930B: 1.23m CAHA optical observations
  6. GRB 140930B: MASTER early optical observations
  7. GRB140928A: Gemini-South observation
  8. GRB 140928A: LCO-Cerro Tololo further observations
  9. GRB 140928A: LCO-Cerro Tololo observations
  10. GRB 140928A: GROND Afterglow Candidate
  11. GRB 140928A: Swift-XRT observations
  12. GRB 140927A: Swift-UVOT analysis
  13. GRB 140919A: Swift/UVOT Detection
  14. GRB 140919A: GROND afterglow candidate
  15. GRB 140919A: Swift/UVOT observations
  16. GRB 140919A: Swift-XRT observations
  17. GRB 140916B: LOT and iPTF follow-up of optical afterglow candidates
  18. Swift detection of outburst from 4U 1700+24
  19. GRB 140916A: Swift/UVOT Upper Limits
  20. GRB 140916A: UKIRT J-band observations
  21. GRB 140916B: iPTF Optical Observations
  22. GRB 140916A: FTS observations
  23. GRB 140907A: Continued DCT Observations
  24. Possible radio detection of GRB 140903A with the GMRT
  25. GRB 140907A: Mondy optical observations
  26. GRB 140903A: Chandra detection of the afterglow
  27. GRB 140909A: Swift/UVOT Upper Limits
  28. GRB 140909A: Swift-XRT observations
  29. GRB 140907A: 1.23m CAHA optical observations
  30. GRB 140907A: TShAO observations
  31. GRB 140907A: MASTER optical observations
  32. GRB 140907A: Nishi-Harima NIR Observations
  33. GRB 140907A: Discovery Channel Telescope observations
  34. GRB 140907A: T100 observations
  35. GRB 140907A: redshift from the 10.4m GTC telescope
  36. GRB 140907A : Virtual Telescope optical observations
  37. GRB140907A: Swift UVOT detection
  38. GRB 140907A : Optical observations from Nanshan
  39. GRB 140906A - Fermi GBM Detection
  40. GRB 140906A: iPTF optical transient candidates
  41. GRB 140903A: Possible optical variability
  42. GRB 140903A: NOT optical and NIR observations
  43. GRB 140901B: Swift XRT observation
  44. GRB 140903A: FTN observations
  45. GRB 140903A: ISON-Kislovodsk observations
  46. GRB 140903A: 6 GHz VLA detection
  47. GRB 140903A: tentative spectroscopic redshift
  48. GRB 140903A: Swift/UVOT Upper Limits
  49. GRB 140903A: P60 Optical Observations
  50. GRB140903A: Discovery Channel Telescope Optical Detection
  51. GRB 140831A: iPTF observations of a possible short burst detected by Fermi GBM
  52. GRB 140829A: iPTF optical observations
  53. IPN Triangulation of GRB 140824B
  54. GRB 140818B: TLS observations
  55. GRB 140824B: Swift observations
  56. Fermi TRIGGER_NUM 430645968: MASTER OT inside error box
  57. Swift Mission Operations Center Moving Tomorrow
  58. Fermi TRIGGER_NUM 430583595: MASTER OT 20 hours later
  59. Fermi TRIGGER_NUM 430583595: MASTER OT JR011101.13+603337.5 detection
  60. GRB 140824A: OSN optical limit
  61. GRB 140824A: Swift/UVOT Upper Limits
  62. GRB 140817A: NOT optical observations
  63. Fermi GBM Trigger 140819576/ 430148973/ MASTER OT
  64. Fermi trigger 430148973: Swift-XRT observation
  65. GRB 140818A: GROND confirmation of afterglow candidate
  66. GRB 140808A/iPTF14eag: AMI 15 GHz detection
  67. GRB140819A: Deep GROND Upper Limits
  68. Fermi 430148973/MASTER candidate: LCO-Sutherland observations
  69. Fermi trigg_num 430148973: OSN I-band observations
  70. GRB 140818B: Swift/UVOT Upper Limits
  71. Radio upper limit on the GRB 140808A with the GMRT
  72. GRB140818B : GROND afterglow candidate
  73. GRB 140818B: OSN I-band afterglow candidate
  74. GRB 140817A: Swift/UVOT Afterglow Detection
  75. Swift detection of SAX J1712.6-3739
  76. GRB 140818A: Swift-XRT and UVOT potential afterglow detection
  77. GRB 140818A Tiled Swift observations
  78. GRB 140808A / PTFeag: VLA K-band observations
  79. GRB 140815A: GROND afterglow candidate
  80. GRB 140815A: Swift-XRT observations
  81. GRB 140814A: Swift-XRT and UVOT observations
  82. GRB 140814A: MASTER optical follow-up inspection
  83. GRB 140814A: Swift-XRT and UVOT observations
  84. Swift Mission Operations Center Moving
  85. Swift trigger 609139 is probably 4U 1850-03
  86. Swift observations of possible GRB 140809A candidate
  87. GRB 140809A : Virtual Telescope optical observations
  88. GRB 140809A (FERMI trigger 429246673): MASTER follow-up inspection
  89. GRB 140808A: Swift/UVOT Upper Limits
  90. GRB 140808A: Redshift from the 10.4m GTC telescope
  91. GRB 140808A: Swift-XRT observations
  92. GRB 140808A: optical afterglow candidate iPTF14eag
  93. GRB 140801A: AAO optical observations
  94. GRB 140801A: GROND Afterglow detection, unbroken decay
  95. GRB140801A: Swift/XRT further observations
  96. GRB 140730A: GROND Upper limits
  97. GRB 140801A: BTA confirmation of redshift
  98. GRB 140801A: Swift-XRT observations
  99. GRB 140801A : Virtual Telescope optical observations
  100. GRB 140801A: Redshift from the 10.4m GTC telescope

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