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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

16273 results found.

  1. GRB 141026A: RATIR Optical Observations
  2. GRB 141020A: AAO optical upper limit
  3. GRB 141020A: Khureltogot optical upper limit
  4. GRB 141022A: Swift/UVOT Upper Limits
  5. GRB 141020A: Mondy optical observations
  6. GRB141015A iTelescope observation
  7. GRB 141022A: GROND Detection of a possible Optical Afterglow Candidate
  8. GRB 141004A: RATIR Late Time Optical and NIR Observations
  9. GRB 141004A: La Palma late-time observations and possible brightening
  10. GRB 141020A: Swift detection of a burst with an optical counterpart
  11. GRB 141015A: MITSuME Akeno upper limits
  12. GRB 141017A: Zadko observatory - Gingin optical observations
  13. GRB 141015A: Swift/UVOT Upper Limits
  14. GRB 141015A: MITSuME Okayama upper limits
  15. GRB 141015A: RATIR Optical Upper Limits
  16. GRB 141015A: Super-LOTIS early observations
  17. GRB 141015A: ISON-NM early optical observations
  18. Trigger 614903: Swift detection of IGR J17544-2619
  19. GRB 141005A: iTelescope.Net T21 Optical Observation
  20. GRB141004A: Host galaxy redshift form GTC
  21. GRB 141005A: Additional P60 imaging and afterglow confirmation
  22. GRB 141005A: Swift/UVOT Upper Limits
  23. GRB141004A: NOT imaging and spectroscopy
  24. GRB 141004A: Swift/UVOT Detection
  25. GRB 141004A: RATIR Optical Observations
  26. GRB 141004A: Monte Agliale Observatory optical observations
  27. GRB 141005A: RATIR Optical Observations
  28. GRB 141005A: P60 probable afterglow deteaction
  29. GRB 141004A: TNG photometric and spectroscopic observations
  30. GRB 141004A: 1.23m CAHA optical observations
  31. GRB 141004A: Swift detection of a burst with an optical counterpart
  32. Swift observations of HD 305560
  33. GRB 140928A: Swift-XRT follow-up observations
  34. Swift possible detection of the Be star HD 305560
  35. GRB 140930B: Gemini South Spectroscopy
  36. GRB 140930A/MAXI J2259+524: MASTER optical observations
  37. GRB 140930B: Swift/UVOT Upper Limits
  38. GRB 140930B: MMT confirmation of the optical afterglow
  39. GRB 140930B: ISON-Kislovodsk observations
  40. GRB 140930B: 1.23m CAHA optical observations
  41. GRB 140930B: MASTER early optical observations
  42. GRB 140928A: LCO-Cerro Tololo further observations
  43. GRB 140928A: LCO-Cerro Tololo observations
  44. GRB 140928A: GROND Afterglow Candidate
  45. GRB 140919A: Swift/UVOT Detection
  46. GRB 140916B: LOT and iPTF follow-up of optical afterglow candidates
  47. Swift detection of outburst from 4U 1700+24
  48. GRB 140916A: Swift/UVOT Upper Limits
  49. GRB 140916A: MITSuME Okayama upper limits
  50. GRB 140916B: iPTF Optical Observations
  51. GRB 140916A: FTS observations
  52. GRB 140907A: Continued DCT Observations
  53. GRB 140907A: Mondy optical observations
  54. GRB 140903A: Chandra detection of the afterglow
  55. GRB 140909A: Swift/UVOT Upper Limits
  56. GRB 140907A: 1.23m CAHA optical observations
  57. GRB 140907A: MASTER optical observations
  58. GRB 140907A: MITSuME Akeno Optical Observation
  59. GRB 140907A: Discovery Channel Telescope observations
  60. GRB 140907A: redshift from the 10.4m GTC telescope
  61. GRB 140907A: MITSuME Ishigakijima Optical Observation
  62. GRB140907A: MITSuME Okayama Optical Observation
  63. GRB 140907A : Virtual Telescope optical observations
  64. GRB140907A: Swift UVOT detection
  65. GRB 140907A : Optical observations from Nanshan
  66. GRB 140907A: Swift detection of a burst with an optical counterpart
  67. GRB 140906A - Fermi GBM Detection
  68. GRB 140906A: iPTF optical transient candidates
  69. GRB 140903A: Confirmation of Optical Fading from Discovery Channel Telescope
  70. GRB 140903A: Possible optical variability
  71. GRB 140903A: NOT optical and NIR observations
  72. GRB 140903A: FTN observations
  73. GRB 140818B: TShAO optical upper limit
  74. GRB 140903A: 6 GHz VLA detection
  75. GRB 140903A: Swift/UVOT Upper Limits
  76. GRB 140903A: P60 Optical Observations
  77. GRB140903A: Discovery Channel Telescope Optical Detection
  78. GRB 140903A: Coincident galaxy cluster in archival images
  79. GRB 140831A: iPTF observations of a possible short burst detected by Fermi GBM
  80. GRB 140829A: Fermi GBM Detection
  81. GRB 140829A: iPTF optical observations
  82. IPN Triangulation of GRB 140824B
  83. GRB 140824A: optical upper limit in CrAO
  84. GRB 140824B: Swift observations
  85. GRB 140824A: NOT optical upper limits
  86. GRB 140824A: OSN optical limit
  87. GRB 140824A: MITSuME Ishigakijima upper limits
  88. GRB 140824A: Swift/UVOT Upper Limits
  89. GRB 140817A: NOT optical observations
  90. GRB 140817A: Khureltogot optical upper limit
  91. GRB 140818B: ISON-Kislovodsk and ISON-Burakan optical upper limit
  92. Fermi trigger 430148973: Swift-XRT observation
  93. GRB 140818A: GROND confirmation of afterglow candidate
  94. GRB 140808A/iPTF14eag: AMI 15 GHz detection
  95. GRB140819A: Deep GROND Upper Limits
  96. Fermi trigg_num 430148973: OSN I-band observations
  97. Fermi trigg_num 430148973: bright OT inside large error box!
  98. GRB 140818B: Swift/UVOT Upper Limits
  99. Radio upper limit on the GRB 140808A with the GMRT
  100. GRB 140818B: OSN I-band afterglow candidate

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