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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"

20949 results found.

  1. GRB 141229A: 1.23m CAHA optical observations
  2. GRB 141229A: Swift-XRT observations
  3. Christmas GRB 141225A: GROND Observations
  4. GRB 141229A Tiled Swift observations
  5. GRB 141225A: TAROT Calern observatory optical observations
  6. GRB 141225A: Swift/UVOT refined analysis
  7. GRB 141225A: very early T60 observations
  8. GRB 141225A: MASTER-SAAO first OT detection
  9. GRB 141225A: Nanshan very early optical observations
  10. GRB 141225A: Redshift from OSIRIS at the 10.4m GTC
  11. GRB 141225A: Optical aftergow confirmation
  12. GRB 141225A: 1.23m CAHA optical observations
  13. GRB 141221A: TAROT La Silla observatory optical observations
  14. Swift XRT and UVOT observations of GRB141222A
  15. GRB 141221A: Continued Skynet PROMPT-CTIO observations
  16. GRB 141221A: Swift/UVOT Detection
  17. GRB 141215A: further Swift-XRT observations and afterglow detection
  18. GRB141221A: GROND Afterglow Detection
  19. GRB 141221A: Skynet PROMPT-CTIO observations of the optical afterglow
  20. GRB 141221A: LCOGT-McDonald optical afterglow observations
  21. GRB141221A: REM afterglow
  22. GRB 141220A: Swift/UVOT Detection
  23. GRB 141220A: Photometry from OSIRIS/GTC
  24. GRB 141220A: LT optical afterglow observations
  25. GRB 141220A: Redshift from OSIRIS at the 10.4m GTC
  26. GRB141220A: 1.23m CAHA I-band observations
  27. GRB 141121A: Keck observations
  28. GRB 141215A: Swift-XRT observations
  29. GRB 141215A Tiled Swift observations
  30. GRB 141212A: Zadko observatory - Gingin optical observations
  31. GRB 141212A: Swift/UVOT Upper Limits
  32. GRB 141212B: Swift/UVOT Upper Limits
  33. GRB 141212A: VLA upper limit
  34. GRB 141212A: extended object within the XRT error circle
  35. GRB 141212A: 1.23m CAHA I-band observations
  36. GRB 141212B: initial Swift/UVOT observations
  37. GRB 141212B: Swift/XRT preliminary localization
  38. GRB 141212A: MASTER early optical observations
  39. GRB 141212A: Skynet R-COP Observations
  40. GRB 141207A: Swift-XRT afterglow candidate detection
  41. GRB 141121A: further VLA observations
  42. GRB141208.63: MASTER OT Detection During the Fermi Error Box inspection
  43. GRB141202A: Discovery Channel Telescope Optical Observations
  44. GRB141207A: Discovery Channel Telescope Optical Observations
  45. GRB 141207A: Swift-UVOT Observations
  46. GRB 141207A: Swift-XRT observations
  47. GRB 141207A Tiled Swift observations
  48. GRB141121A: Discovery Channel Telescope Optical Observations
  49. GRB 141205A: Swift/UVOT Upper Limits
  50. GRB 141205A: Nanshan optical upper limit
  51. GRB 141205A: XRT observations
  52. GRB 141202A: Swift/UVOT Detection of a Variable Source Near the IPN Error Box
  53. GRB 141121A: Mondy optical observations
  54. GRB 141130A: Mondy optical observations
  55. GRB 141202A: Swift XRT observations
  56. GRB 141202A Tiled Swift observations
  57. GRB 141130A: Mondy optical light curve
  58. GRB 141030A: Nanshan very early optical observations
  59. GRB 141121A: Continued RATIR Optical Observations
  60. GRB 141130A: Swift/UVOT Detection
  61. GRB 141130A: Nanshan optical observations
  62. GRB 141130A: Mondy optical observations
  63. GRB 141121A: Continued RATIR Optical Observations
  64. GRB 141121A: Mondy optical observations
  65. GRB 141121A: TSHAO optical observations
  66. GRB 141121A: Continued RATIR Optical Observations
  67. GRB 141121A: RATIR Optical Observations - Errata for GCN 17105
  68. GRB 141121A: Khureltogot optical observations
  69. GRB 141121A: Mondy optical observations
  70. GRB 141121A: SPI-ACS/INTEGRAL observations
  71. GRB 141121A: RATIR Optical and NIR Observations
  72. GRB 141121A: three epochs of SAO RAS optical observations
  73. GRB 141121A: Continued RATIR Optical Observations
  74. GRB 141121A: WSRT radio detection
  75. GRB 141121A: TSHAO optical observations
  76. GRB 141121A: Continued Mondy optical observations
  77. GRB 141121A: Continued RATIR Optical Observations
  78. GRB 141121A: RATIR Optical Observations - Steeper Fading
  79. GRB 141121A: AMI 15 GHz detection
  80. GRB 141121A: RATIR Optical Observations - Fading Again
  81. GRB141124A: MASTER Detection of New Flare of QSO NVSS J075043+790917 During the Fermi Error Box inspection
  82. GRB 141121A: Mondy optical observations
  83. GRB 141121A: LCO-FTN rebrightening confirmation
  84. GRB 141121A: Continued RATIR Optical Observations - Rebrightening
  85. GRB 141121A: AAO optical observations
  86. GRB 141121A: Continued RATIR Optical Observations
  87. GRB 141121A: Swift/UVOT Detections
  88. GRB 141121A: RATIR Optical Observations
  89. GRB 141121A: LCO-FTN observations
  90. GRB 141118A: iPTF Optical Observations
  91. GRB 141121A: GROND Afterglow candidate
  92. GRB 141121A: MAXI/GSC detection
  93. GRB141121A: BOOTES-2/TELMA upper limit
  94. GRB 141109A: further VLA observations
  95. GRB 141104A: further Swift-XRT observations and afterglow candidate
  96. GRB 141109A: VLA detection
  97. Trigger 618634: Swift detection of Vela X-1
  98. GRB 141015A: TAROT La Silla observatory optical observations
  99. GRB 141022A: TAROT La Silla observatory optical observations
  100. GRB 141031A: TAROT La Silla observatory optical observations

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