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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"

2744 results found.

  1. Swift XRT status update
  2. Swift XRT is off-line
  3. Chandra late-time observations of GRB140515A
  4. Swift Trigger 600114 in M31: Archival and Prompt UVOT Imaging
  5. IPN Triangulation of GRB 140523A
  6. GRB 140523A: Nanshan optical upper limit
  7. GRB 140523A: possible X-ray afterglow candidate from tiled Swift/XRT observations
  8. GRB 140518A: RATIR Optical and NIR Observations
  9. GRB 140502A: ISON-NM early optical limit
  10. GRB 140428A: Swift-XRT detection of a source
  11. GRB 140428A: Swift Detection of a Possible Burst
  12. GRB 140423A: Nishi-Harima NIR Observations
  13. GRB 140423A: Swift/UVOT detection of a possible counterpart
  14. Konus-Wind observation of GRB 140413A
  15. Swift Trigger 595616: a possible GRB
  16. Swift-BAT trigger 595162 is noise
  17. Swift Trigger 595162: a possible GRB
  18. Swift trigger 594286: Is likely a noise trigger
  19. GRB 140330A: intense and persistent gamma-ray emission detected by AGILE
  20. GRB 140226A/iPTF14yb: Mondy optical observations
  21. GRB 140320C: Mondy optical observations and afterglow confirmation
  22. GRB 140311C: MASTER optical observations
  23. GRB 140311C: Swift-XRT and UVOT observations
  24. Fermi416242156: possible iPTF counterpart
  25. GRB 140226A/iPTF14yb: Mondy optical observations
  26. GRB 140219A: Mondy optical observations of XRT source #5
  27. Konus-Wind observation of GRB 140226A
  28. IPN triangulation of GRB 140226A, a possible GRB counterpart to iPTF14yb
  29. iPTF14yb: Swift-XRT detection
  30. GRB 140219A: Xuyi and Nanshan upper limits
  31. GRB 140209A, Swift-BAT refined analysis
  32. GRB 140209A: optical observations
  33. GRB 140206A: theoretical prediction of redshift and of supernova occurrence
  34. GRB 140110A: Second Follow-up Swift-XRT Observation
  35. GRB 140104B: Further Swift XRT observations
  36. GRB 140108A: theoretical prediction of redshift and of supernova occurrence
  37. GRB 140105A/Fermi410578384: MASTER-Net early optical observations
  38. Fermi410578384: iPTF optical afterglow candidates for a possible short GRB
  39. GRB 131202A: theoretical estimation of the redshift
  40. GRB 060614: theoretical derivation of the redshift and need for deeper search of the host galaxy
  41. GRB 131128A: Swift detection of a burst
  42. GRB 131122A: i-band observations from NOT
  43. IPN Triangulation of GRB 131118A
  44. GRB 130925A: HST imaging
  45. GRB 131108A: 1.23m CAHA optical candidate
  46. GRB 131108A: Swift detection of a possible X-ray afterglow
  47. GRB 131103A: Swift detection of a burst
  48. GRB 131024C: ICSP discovery of a burst in X-rays by balloon borne study
  49. IPN Triangulation of GRB 131028A (long/bright)
  50. Swift Trigger 575905/possible GRB 131026A: Swift-XRT observations
  51. Swift Trigger 575905: a possible GRB
  52. IPN triangulation of GRB 131011B (Swift Trigger 574266)
  53. IPN Triangulation of GRB 131014A
  54. GRB 131014A: RATIR Optical and NIR Observations
  55. GRB 131014A: NOT afterglow candidate
  56. GRB 131014A: Nanshan optical observations
  57. GRB 131014A: Swift detection of a possible X-ray afterglow
  58. Fermi403206457: continued P60 observations and fading behavior
  59. Fermi403206457: iPTF detection of a possible optical afterglow
  60. GRB 130925A: Possible signatures of binary nature in the afterglow - Request for observations
  61. GRB131004A: TNG Redshift confirmation
  62. GRB131004A: Magellan Redshift
  63. GRB 131004A: TNG optical afterglow confirmation
  64. GRB 130925A: continuing Swift/XRT monitoring
  65. Konus-Wind observation of GRB 130925A
  66. Observation of possible GRB/TDE 130925A by INTEGRAL/SPI-ACS: three activity episodes
  67. Fermi GBM detection of GRB 130925A and a possible precursor
  68. GRB 130925A: Swift-XRT refined Analysis
  69. GRB 130831A: Maidanak optical observations, possible emerging Supernova
  70. GRB 130913A detected in ground analysis of Swift-BAT data
  71. GRB 130912A: REM optical/NIR upper limits
  72. GRB 130907A: Early Tautenburg detections, red afterglow
  73. GRB 130907A: Skynet DSO-14/Yerkes-41 detections of a possible afterglow
  74. Swift follow-up results of the possible weak INTEGRAL GRB
  75. Swift follow-up of an INTEGRAL possible weak GRB
  76. Swift Trigger 569022: a possible GRB
  77. IPN triangulation of GRB 130828A
  78. IPN triangulation of GRB130821A
  79. GRB 130821A: Swift-XRT observation
  80. Refined IPN Triangulation of GRB 130812B
  81. GRB 130806A: Swift detection of a burst
  82. GRB130803A: GROND detection of possible host
  83. GRB 130722A: Swift/UVOT Detection
  84. GRB 130626A: Retraction of possible X-ray afterglow
  85. GMRT radio detection of GRB 130702A
  86. GRB 130702A: Maidanak optical observations
  87. GRB 130702A (= Fermi 394416326): correction of the GCN #14988 title
  88. GRB 130702A: NOT spectroscopy and redshift of the nearby bright galaxy
  89. Fermi GRB 130702A: Swift XRT and UVOT observations
  90. GRB 130702A / Fermi394416326 : Fermi-LAT detection of a burst
  91. Fermi394416326: FTN detection
  92. Fermi394416326: iPTF detection of a possible optical afterglow
  93. GRB 130627B: Possible Swift-XRT afterglow detection
  94. GRB 130626A: Swift-XRT possible detection and UVOT upper limits
  95. GRB 130603B: Analogy with GRB 090510A and possible connection with a supernova
  96. GRB 130603B: Detection of possible afterglow/kilonova in HST observations
  97. GMRT radio observation of GRB 130603B
  98. GRB 130606A: Errata Ks magnutide in GCN 14792
  99. Swift/UVOT observations of GRB130603A
  100. Swift Trigger 556533 is probably not an astrophysical event

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