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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"

20960 results found.

  1. GRB041218: optical observations
  2. GRB041218: Continued P60 Optical Observations
  3. GRB 041219: Infrared Afterglow Candidate
  4. GRB 041219: Infrared Afterglow Candidate
  5. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  6. GRB041219: P60 Optical Observations
  7. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  8. GRB 041217: PROMPT Observations
  9. GRB041218: optical observations
  10. GRB 041218; optical candidate
  11. GRB 041218: Optical observations
  12. GRB 041217: LCO40 Optical Observations and Possible Candidates
  13. GRB041217: Optical Observations
  14. GRB041217: NIR and optical observations with REM
  15. GRB041217: P60 Optical Observations
  16. GRB041217: Infrared Observations
  17. GRB041211: Faulkes Telescope continued optical monitoring
  18. Optical transient (GRB?) in Lynx
  19. Optical transient (GRB?) in Lynx, UT Dec 11.4436
  20. GRB041211: Continued P60 Observations
  21. GRB041211: RAPTOR observations
  22. GRB041211, Faulkes Telescope optical observation
  23. GRB 041211: Infrared Observations
  24. GRB 041211: KAIT observations
  25. GRB 041211: Optical follow-up in East Asian region
  26. GRB970815: Discovery of Optical Afterglow
  27. GRB041015: Near-Infrared observations
  28. GRB 040924: Afterglow Color
  29. GRB 041006: GETS Optical Afterglow Observation
  30. GRB 041006: Optical Observations
  31. GRB041006, late-time optical photometry
  32. GRB041006: RTT150 Optical Observations
  33. GRB041015 : Multi epoch optical observations
  34. HST Observations: XRF 040701 and 040812
  35. GRB041006: RTT150 Optical Observations
  36. GRB 041016:Optical limit during first minute
  37. GRB041016: MASTER: Optical observations
  38. GRB 041015: Optical Observations at Rikubetsu
  39. GRB041006: Near Infrared observations
  40. GRB 041015 R band observations
  41. GRB041015: MASTER: Optical observations
  42. GRB041006: Fading X-ray Afterglow Observed with Chandra
  43. GRB 041006 R observations in Loiano
  44. GRB041006: VLT observations of the afterglow and host galaxy
  45. GRB041006: Optical observations and Potential host galaxy
  46. GRB 041006: SARA afterglow observations
  47. Search for SN light in XRF 040912 with MEGACAM
  48. GRB 040916: Afterglow Color at Early Times
  49. GRB 041006 Optical afterglow observations
  50. IBAS GRB Alert # 2010
  51. GRB 041006: BR observations with VATT
  52. GRB 041006: Redshift confirmed
  53. GRB041006: Liverpool Telescope optical observations
  54. GRB 041006: Colour measurement
  55. GRB 041006: Radio Observations
  56. GRB041006, further submilllimetre observations
  57. GRB041006: Optical photometry and spectroscopy at TNG
  58. GRB041006 (= H3570): Chandra Observations In Progress
  59. GRB041006, optical I observation
  60. GRB041006 (=HETE3570): optical observations
  61. ROTSE-IIIa Observations of GRB 041006
  62. GRB041006, submillimetre observations
  63. GRB041006: MASTER optical observations
  64. GRB 041006: Optical decay
  65. Very strong outburst from SGR 1806-20 detected with INTEGRAL
  66. XRF 020903: Observations of the Host Galaxy (authors)
  67. XRF 020903: Observations of the Host Galaxy
  68. SGR 1806-20 still active
  69. GRB 040924: Second Epoch WSRT Radio Observations
  70. radio observations, GRB 040924
  71. GRB040929: MASTER optical observations
  72. Konus-Wind and Helicon-Coronas-F observations of GRB040924
  73. GRB040924,optical observation
  74. GRB040924, RTT150 optical observation
  75. GRB040924, RTT150 optical observation
  76. GRB040924: KAIT observations
  77. GRB 040924: WSRT Radio Observations
  78. GRB040924 : Optical candidate observations at Lulin observatory
  79. GRB040924 : Optical candidate observations at Lulin observatory
  80. GRB040924: Optical afterglow properties
  81. GRB 040924: RTT150 optical observations
  82. GRB040924: MASTER Optical observations
  83. GRB040924 (H3564): Optical afterglow candidate
  84. XRF 040912: Radio Observations
  85. XRF 040916: Radio Observations
  86. XRF040916: continuing decay of OT
  87. TAROT Observations of GRB 040916 (HETE #3558)
  88. GRB040912(=H3557): Candidate Optical Afterglow
  89. XRF040916, optical observations
  90. XRF 040912, identification of CXO sources
  91. XRF040916, Ic observations
  92. XRF040916: optical follow-up observations
  93. GRB040916: Archival optical observations
  94. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  95. GRB040916: Optical observations
  96. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  97. GRB040912 (= H3557): Chandra Observations Scheduled
  98. GRB 040912: Optical Observations
  99. GRB/XRF040912,optical observations
  100. GRB 040912, BVRI observations

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