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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"

20967 results found.

  1. GRB 041219 Optical Observations
  2. GRB041219: Optical Afterglow Detection
  3. GRB041219: Continued NIR Observations
  4. GRB 041219: Radio Afterglow Detection
  5. GRB 041218 : Radio Observations
  6. GRB 041218: R-band optical observations
  7. GRB041218: Liverpool Telescope optical observations
  8. GRB041218: optical observations
  9. GRB041218: Continued P60 Optical Observations
  10. GRB 041219: Infrared Afterglow Candidate
  11. GRB 041219: Infrared Afterglow Candidate
  12. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  13. GRB041219: P60 Optical Observations
  14. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  15. GRB 041217: PROMPT Observations
  16. GRB041218: optical observations
  17. GRB 041218; optical candidate
  18. GRB 041218: Optical observations
  19. GRB 041217: LCO40 Optical Observations and Possible Candidates
  20. GRB041217: Optical Observations
  21. GRB041217: NIR and optical observations with REM
  22. GRB041217: P60 Optical Observations
  23. GRB041217: Infrared Observations
  24. GRB041211: Faulkes Telescope continued optical monitoring
  25. Optical transient (GRB?) in Lynx
  26. Optical transient (GRB?) in Lynx, UT Dec 11.4436
  27. GRB041211: Continued P60 Observations
  28. GRB041211: RAPTOR observations
  29. GRB041211, Faulkes Telescope optical observation
  30. GRB 041211: Infrared Observations
  31. GRB 041211: KAIT observations
  32. GRB 041211: Optical follow-up in East Asian region
  33. GRB970815: Discovery of Optical Afterglow
  34. GRB041015: Near-Infrared observations
  35. GRB 040924: Afterglow Color
  36. GRB 041006: GETS Optical Afterglow Observation
  37. GRB 041006: Optical Observations
  38. GRB041006, late-time optical photometry
  39. GRB041006: RTT150 Optical Observations
  40. GRB041015 : Multi epoch optical observations
  41. HST Observations: XRF 040701 and 040812
  42. GRB041006: RTT150 Optical Observations
  43. GRB 041016:Optical limit during first minute
  44. GRB041016: MASTER: Optical observations
  45. GRB 041015: Optical Observations at Rikubetsu
  46. GRB041006: Near Infrared observations
  47. GRB 041015 R band observations
  48. GRB041015: MASTER: Optical observations
  49. GRB041006: Fading X-ray Afterglow Observed with Chandra
  50. GRB 041006 R observations in Loiano
  51. GRB041006: VLT observations of the afterglow and host galaxy
  52. GRB041006: Optical observations and Potential host galaxy
  53. GRB 041006: SARA afterglow observations
  54. Search for SN light in XRF 040912 with MEGACAM
  55. GRB 040916: Afterglow Color at Early Times
  56. GRB 041006 Optical afterglow observations
  57. IBAS GRB Alert # 2010
  58. GRB 041006: BR observations with VATT
  59. GRB 041006: Redshift confirmed
  60. GRB041006: Liverpool Telescope optical observations
  61. GRB 041006: Colour measurement
  62. GRB 041006: Radio Observations
  63. GRB041006, further submilllimetre observations
  64. GRB041006: Optical photometry and spectroscopy at TNG
  65. GRB041006 (= H3570): Chandra Observations In Progress
  66. GRB041006, optical I observation
  67. GRB041006 (=HETE3570): optical observations
  68. ROTSE-IIIa Observations of GRB 041006
  69. GRB041006, submillimetre observations
  70. GRB041006: MASTER optical observations
  71. GRB 041006: Optical decay
  72. Very strong outburst from SGR 1806-20 detected with INTEGRAL
  73. XRF 020903: Observations of the Host Galaxy (authors)
  74. XRF 020903: Observations of the Host Galaxy
  75. SGR 1806-20 still active
  76. GRB 040924: Second Epoch WSRT Radio Observations
  77. radio observations, GRB 040924
  78. GRB040929: MASTER optical observations
  79. Konus-Wind and Helicon-Coronas-F observations of GRB040924
  80. GRB040924,optical observation
  81. GRB040924, RTT150 optical observation
  82. GRB040924, RTT150 optical observation
  83. GRB040924: KAIT observations
  84. GRB 040924: WSRT Radio Observations
  85. GRB040924 : Optical candidate observations at Lulin observatory
  86. GRB040924 : Optical candidate observations at Lulin observatory
  87. GRB040924: Optical afterglow properties
  88. GRB 040924: RTT150 optical observations
  89. GRB040924: MASTER Optical observations
  90. GRB040924 (H3564): Optical afterglow candidate
  91. XRF 040912: Radio Observations
  92. XRF 040916: Radio Observations
  93. XRF040916: continuing decay of OT
  94. TAROT Observations of GRB 040916 (HETE #3558)
  95. GRB040912(=H3557): Candidate Optical Afterglow
  96. XRF040916, optical observations
  97. XRF 040912, identification of CXO sources
  98. XRF040916, Ic observations
  99. XRF040916: optical follow-up observations
  100. GRB040916: Archival optical observations

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