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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

8473 results found.

  1. GRB 050315: Absorption redshift
  2. Swift-BAT detection of GRB 050315
  3. GRB 050306: Radio Observations
  4. GRB 050306: Confirmation of X-ray afterglow
  5. GRB 050309, Early optical limits from RAPTOR
  6. GRB 050306: CORRECTION to date of observation
  7. GRB 050306: R-band observations
  8. GRB 050306: No Swift UVOT Optical Counterpart Detected
  9. GRB 050306: REM optical-infrared observations
  10. GRB 050306: Possible X-ray Afterglow Position from the Swift
  11. Ongoing activity of SGR 1806-20 after the giant flare
  12. GRB 050126: Confirmation of the NIR afterglow candidate
  13. GRB 050219b: candidate NIR afterglow
  14. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  15. GRB 050215B: Radio Observations
  16. GRB 050215b: XRT confirmation of IR afterglow candidate
  17. GRB050215b: P60 Optical Observations
  18. GRB 050215b: Swift XRT Source Variability
  19. GRB 050215B: candidate afterglow
  20. GRB 050124: Radio Observations
  21. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  22. GRB 050126: Radio Observations
  23. GRB 050128: Swift XRT prompt afterglow position
  24. GRB 050124: NIR Candidates from Keck/NIRC
  25. GRB 050123 : I-band follow-up observation
  26. Unusual optical transient (GRB ???)
  27. Detection of the SGR 1806-20 giant outburst back-scattered by the
  28. GRB041223: decay of the afterglow
  29. GRB041223: optical and NIR observations with REM
  30. Very high activity of SGR 1806-20
  31. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  32. GRB 041219 : optical follow-up observations
  33. Deep RAPTOR observations during GRB 041219
  34. GRB041218: Continued P60 Optical Observations
  35. GRB 041219: Infrared Afterglow Candidate
  36. GRB 041219: Infrared Afterglow Candidate
  37. GRB 041217: PROMPT Observations
  38. GRB041218: optical observations
  39. GRB 041218; optical candidate
  40. GRB 041218: Optical observations
  41. GRB041211, Faulkes Telescope optical observation
  42. Summary of the recent bursts from SGR 1806-20
  43. Bright bursts from SGR1806-20
  44. GRB041006: Fading X-ray Afterglow Observed with Chandra
  45. GRB 040924: VLT spectroscopy
  46. GRB 041006 : Optical follow-up observation at TAROT
  47. GRB041006: Fading of optical afterglow candidate
  48. GRB 041006 : Optical follow-up observation at KISO
  49. GRB 041006: Finding chart
  50. GRB 041006: Optical afterglow candidate
  51. radio observations, GRB 040924
  52. GRB040924,optical observation
  53. GRB 040924: detection of possible host galaxy by Subaru
  54. GRB040924, RTT150 optical observation
  55. GRB040924: Afterglow magnitude at t=17.5hr
  56. GRB040924 : Optical candidate observations at Lulin observatory
  57. GRB040924 : Optical candidate observations at Lulin observatory
  58. GRB 040924: Subaru NIR observation
  59. GRB040924: Optical afterglow properties
  60. IPN triangulation of GRB040924 (H3564)
  61. GRB040924 (H3564): Optical afterglow candidate
  62. XRF 040912: Radio Observations
  63. XRF 040916: Radio Observations
  64. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  65. XRF040916: continuing decay of OT
  66. TAROT Observations of GRB 040916 (HETE #3558)
  67. GRB040912(=H3557): Candidate Optical Afterglow
  68. XRF040916, optical observations
  69. XRF040916: Optical Transient Candidate by Subaru
  70. XRF040916, Ic observations
  71. XRF040916: optical follow-up observations
  72. GRB040916: Archival optical observations
  73. GRB040916: Optical observations
  74. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  75. GRB 040912, BVRI observations
  76. An intense burst from SGR1806-20
  77. HETE 3557: Optical observations
  78. GRB 040827 - Radio Observations
  79. GRB040825A: Optical observations
  80. GRB040825A: Optical observations
  81. Increase of SGR 1806-20 activity
  82. GRB 040825: Optical observations
  83. XRF040812: possible afterglow second Chandra observation
  84. GRB 040812: Second epoch CXO Observations
  85. XRF040701: Optical Observations at ESO
  86. Ongoing activity of SGR 1806-20
  87. XRF 040701 - optical observations of the decaying Chandra source
  88. XRF040701: Second-Epoch Chandra Observations
  89. XRF040701: VLA Observations
  90. XRF 040701, optical observations
  91. Activivty of SGR 1806-20
  92. GRB 040511, very fast decay?
  93. GRB 030324: Detection and Color of Host Galaxy
  94. GRB040511: Redshift identifcation
  95. GRB 040511: Optical limit
  96. GRB040511: Candidate optical/NIR afterglow
  97. GRB 040403: Optical Observations
  98. GRB040323: NIR Observations and Variable Object
  99. GRB 031203: spectoscopic evidence for a 1998bw-like SN
  100. MASTER: RXTE GRB040308 optical observation

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