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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"

2797 results found.

  1. GRB 131024C: ICSP discovery of a burst in X-rays by balloon borne study
  2. IPN Triangulation of GRB 131028A (long/bright)
  3. Swift Trigger 575905/possible GRB 131026A: Swift-XRT observations
  4. Swift Trigger 575905: a possible GRB
  5. IPN triangulation of GRB 131011B (Swift Trigger 574266)
  6. IPN Triangulation of GRB 131014A
  7. GRB 131014A: RATIR Optical and NIR Observations
  8. GRB 131014A: NOT afterglow candidate
  9. GRB 131014A: Nanshan optical observations
  10. GRB 131014A: Swift detection of a possible X-ray afterglow
  11. Fermi403206457: continued P60 observations and fading behavior
  12. Fermi403206457: iPTF detection of a possible optical afterglow
  13. GRB 130925A: Possible signatures of binary nature in the afterglow - Request for observations
  14. GRB131004A: TNG Redshift confirmation
  15. GRB131004A: Magellan Redshift
  16. GRB 131004A: TNG optical afterglow confirmation
  17. GRB 130925A: continuing Swift/XRT monitoring
  18. Konus-Wind observation of GRB 130925A
  19. Observation of possible GRB/TDE 130925A by INTEGRAL/SPI-ACS: three activity episodes
  20. Fermi GBM detection of GRB 130925A and a possible precursor
  21. GRB 130925A: Swift-XRT refined Analysis
  22. GRB 130831A: Maidanak optical observations, possible emerging Supernova
  23. GRB 130913A detected in ground analysis of Swift-BAT data
  24. GRB 130912A: REM optical/NIR upper limits
  25. GRB 130907A: Early Tautenburg detections, red afterglow
  26. GRB 130907A: Skynet DSO-14/Yerkes-41 detections of a possible afterglow
  27. Swift follow-up results of the possible weak INTEGRAL GRB
  28. Swift follow-up of an INTEGRAL possible weak GRB
  29. Swift Trigger 569022: a possible GRB
  30. IPN triangulation of GRB 130828A
  31. IPN triangulation of GRB130821A
  32. GRB 130821A: Swift-XRT observation
  33. Refined IPN Triangulation of GRB 130812B
  34. GRB 130806A: Swift detection of a burst
  35. GRB130803A: GROND detection of possible host
  36. GRB 130722A: Swift/UVOT Detection
  37. GRB 130626A: Retraction of possible X-ray afterglow
  38. GMRT radio detection of GRB 130702A
  39. GRB 130702A: Maidanak optical observations
  40. GRB 130702A (= Fermi 394416326): correction of the GCN #14988 title
  41. GRB 130702A: NOT spectroscopy and redshift of the nearby bright galaxy
  42. Fermi GRB 130702A: Swift XRT and UVOT observations
  43. GRB 130702A / Fermi394416326 : Fermi-LAT detection of a burst
  44. Fermi394416326: FTN detection
  45. Fermi394416326: iPTF detection of a possible optical afterglow
  46. GRB 130627B: Possible Swift-XRT afterglow detection
  47. GRB 130626A: Swift-XRT possible detection and UVOT upper limits
  48. GRB 130603B: Analogy with GRB 090510A and possible connection with a supernova
  49. GRB 130603B: Detection of possible afterglow/kilonova in HST observations
  50. GMRT radio observation of GRB 130603B
  51. GRB 130606A: Errata Ks magnutide in GCN 14792
  52. Swift/UVOT observations of GRB130603A
  53. Swift Trigger 556533 is probably not an astrophysical event
  54. GRB 130518A: Swift XRT and UVOT possible afterglow
  55. GRB 130427A: Continued RATIR Optical and NIR Observations - Photometric Evidence for a New Component
  56. GRB 130427A: Skynet detections of a possible supernova
  57. GRB 130514B Swift-BAT observations
  58. GRB 130515A: GROND Observations
  59. GRB 130427A: Tautenburg 2nd epoch: No break, no clear SN
  60. GRB 130427A: host galaxy observations
  61. GRB 130505B: Swift Candidate Afterglow
  62. Refined IPN Triangulation of GRB 130502B
  63. Konus-Wind observation of GRB 130504C
  64. GRB 130504C: Swift-XRT observations
  65. GRB 130502B: possible TNG counterpart
  66. Trigger 555096: Swift detection of a possible burst
  67. GRB 130427A: Pan-STARRS 1 optical observations
  68. GRB 130427A: Predictions about the occurrence of a supernova
  69. GRB 130427A: GMRT radio detection
  70. GRB 130427A: photo-z of possible SDSS host galaxy
  71. GRB 130427A: high energy gamma-ray detection by AGILE
  72. GRB 130427A: Nishi-Harima NIR Observations
  73. GRB 130427A: P60 early nondetection
  74. Trigger 554491: Swift detection of a spike possibly from Sgr A*
  75. GRB 130327B: Swift/XRT source is not the afterglow
  76. Trigger 553930: Swift detection of a possible flare from HR 5110
  77. GRB 130408A, Swift-BAT refined analysis
  78. GRB 130306A: Confirmation of the X-ray Afterglow
  79. Swift Trigger 552142: a possible GRB
  80. GRB 130327A: PAIRITEL NIR Afterglow Candidate
  81. GRB 130315A: Swift detection of a burst
  82. GRB 130313A: Swift-XRT detection of a possible X-ray afterglow
  83. Swift XRT observations of GRB 130310A
  84. GRB 130306A: Swift Detection of a Possible Afterglow
  85. GBM trigger 383712005 (GRB 130228A?) : Possible high-energy photon emission in Fermi/LAT data
  86. GRB 130216A: possible radio counterpart is steady field source
  87. GRB 130216A: possible early detection at 15 GHz
  88. Swift/BAT trigger 547142 is new source Swift J1753.7-2544
  89. Swift Trigger 544381 is unlikely to be a GRB
  90. GRB 121209A: Early CARMA Observations
  91. GRB 121211A: Keck/LRIS redshift
  92. GRB 121202A: TAROT Calern observatory optical observations
  93. GRB 121031A: Fermi GBM detection
  94. GRB 121025A: Confirmation of the X-ray afterglow
  95. GRB 121027A: Swift/UVOT Possible Detection
  96. GRB 121025A: Swift-XRT observation
  97. Swift Trigger 536502 is likely a noise fluctuation in coincidence with SAX J1818.6-1703
  98. Trigger 535733: Swift possible detection of SAX J1828.5-1037
  99. Swift Trigger 535026: Optical decay confirmation with IAC80 and BOOTES-2/TELMA.
  100. GRB 121001A: possible optical counterpart

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