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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"

2803 results found.

  1. GRB 131122A: i-band observations from NOT
  2. IPN Triangulation of GRB 131118A
  3. GRB 130925A: HST imaging
  4. GRB 131108A: 1.23m CAHA optical candidate
  5. GRB 131108A: Swift detection of a possible X-ray afterglow
  6. GRB 131103A: Swift detection of a burst
  7. GRB 131024C: ICSP discovery of a burst in X-rays by balloon borne study
  8. IPN Triangulation of GRB 131028A (long/bright)
  9. Swift Trigger 575905/possible GRB 131026A: Swift-XRT observations
  10. Swift Trigger 575905: a possible GRB
  11. IPN triangulation of GRB 131011B (Swift Trigger 574266)
  12. IPN Triangulation of GRB 131014A
  13. GRB 131014A: RATIR Optical and NIR Observations
  14. GRB 131014A: NOT afterglow candidate
  15. GRB 131014A: Nanshan optical observations
  16. GRB 131014A: Swift detection of a possible X-ray afterglow
  17. Fermi403206457: continued P60 observations and fading behavior
  18. Fermi403206457: iPTF detection of a possible optical afterglow
  19. GRB 130925A: Possible signatures of binary nature in the afterglow - Request for observations
  20. GRB131004A: TNG Redshift confirmation
  21. GRB131004A: Magellan Redshift
  22. GRB 131004A: TNG optical afterglow confirmation
  23. GRB 130925A: continuing Swift/XRT monitoring
  24. Konus-Wind observation of GRB 130925A
  25. Observation of possible GRB/TDE 130925A by INTEGRAL/SPI-ACS: three activity episodes
  26. Fermi GBM detection of GRB 130925A and a possible precursor
  27. GRB 130925A: Swift-XRT refined Analysis
  28. GRB 130831A: Maidanak optical observations, possible emerging Supernova
  29. GRB 130913A detected in ground analysis of Swift-BAT data
  30. GRB 130912A: REM optical/NIR upper limits
  31. GRB 130907A: Early Tautenburg detections, red afterglow
  32. GRB 130907A: Skynet DSO-14/Yerkes-41 detections of a possible afterglow
  33. Swift follow-up results of the possible weak INTEGRAL GRB
  34. Swift follow-up of an INTEGRAL possible weak GRB
  35. Swift Trigger 569022: a possible GRB
  36. IPN triangulation of GRB 130828A
  37. IPN triangulation of GRB130821A
  38. GRB 130821A: Swift-XRT observation
  39. Refined IPN Triangulation of GRB 130812B
  40. GRB 130806A: Swift detection of a burst
  41. GRB130803A: GROND detection of possible host
  42. GRB 130722A: Swift/UVOT Detection
  43. GRB 130626A: Retraction of possible X-ray afterglow
  44. GMRT radio detection of GRB 130702A
  45. GRB 130702A: Maidanak optical observations
  46. GRB 130702A (= Fermi 394416326): correction of the GCN #14988 title
  47. GRB 130702A: NOT spectroscopy and redshift of the nearby bright galaxy
  48. Fermi GRB 130702A: Swift XRT and UVOT observations
  49. GRB 130702A / Fermi394416326 : Fermi-LAT detection of a burst
  50. Fermi394416326: FTN detection
  51. Fermi394416326: iPTF detection of a possible optical afterglow
  52. GRB 130627B: Possible Swift-XRT afterglow detection
  53. GRB 130626A: Swift-XRT possible detection and UVOT upper limits
  54. GRB 130603B: Analogy with GRB 090510A and possible connection with a supernova
  55. GRB 130603B: Detection of possible afterglow/kilonova in HST observations
  56. GMRT radio observation of GRB 130603B
  57. GRB 130606A: Errata Ks magnutide in GCN 14792
  58. Swift/UVOT observations of GRB130603A
  59. Swift Trigger 556533 is probably not an astrophysical event
  60. GRB 130518A: Swift XRT and UVOT possible afterglow
  61. GRB 130427A: Continued RATIR Optical and NIR Observations - Photometric Evidence for a New Component
  62. GRB 130427A: Skynet detections of a possible supernova
  63. GRB 130514B Swift-BAT observations
  64. GRB 130515A: GROND Observations
  65. GRB 130427A: Tautenburg 2nd epoch: No break, no clear SN
  66. GRB 130427A: host galaxy observations
  67. GRB 130505B: Swift Candidate Afterglow
  68. Refined IPN Triangulation of GRB 130502B
  69. Konus-Wind observation of GRB 130504C
  70. GRB 130504C: Swift-XRT observations
  71. GRB 130502B: possible TNG counterpart
  72. Trigger 555096: Swift detection of a possible burst
  73. GRB 130427A: Pan-STARRS 1 optical observations
  74. GRB 130427A: Predictions about the occurrence of a supernova
  75. GRB 130427A: GMRT radio detection
  76. GRB 130427A: photo-z of possible SDSS host galaxy
  77. GRB 130427A: high energy gamma-ray detection by AGILE
  78. GRB 130427A: Nishi-Harima NIR Observations
  79. GRB 130427A: P60 early nondetection
  80. Trigger 554491: Swift detection of a spike possibly from Sgr A*
  81. GRB 130327B: Swift/XRT source is not the afterglow
  82. Trigger 553930: Swift detection of a possible flare from HR 5110
  83. GRB 130408A, Swift-BAT refined analysis
  84. GRB 130306A: Confirmation of the X-ray Afterglow
  85. Swift Trigger 552142: a possible GRB
  86. GRB 130327A: PAIRITEL NIR Afterglow Candidate
  87. GRB 130315A: Swift detection of a burst
  88. GRB 130313A: Swift-XRT detection of a possible X-ray afterglow
  89. Swift XRT observations of GRB 130310A
  90. GRB 130306A: Swift Detection of a Possible Afterglow
  91. GBM trigger 383712005 (GRB 130228A?) : Possible high-energy photon emission in Fermi/LAT data
  92. GRB 130216A: possible radio counterpart is steady field source
  93. GRB 130216A: possible early detection at 15 GHz
  94. Swift/BAT trigger 547142 is new source Swift J1753.7-2544
  95. Swift Trigger 544381 is unlikely to be a GRB
  96. GRB 121209A: Early CARMA Observations
  97. GRB 121211A: Keck/LRIS redshift
  98. GRB 121202A: TAROT Calern observatory optical observations
  99. GRB 121031A: Fermi GBM detection
  100. GRB 121025A: Confirmation of the X-ray afterglow

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