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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').
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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"

3113 results found.

  1. GRB051103:_MASTER_optical_observations
  2. GRB051028: WHT optical candidate
  3. GRB051028: Swift XRT Position
  4. SGR 1806-20: continued moderate activity seen with INTEGRAL
  5. GRB051012: Swift-XRT analysis
  6. GRB 051021B: Refined analysis of the Swift-BAT burst
  7. GRB 051021: SOAR NIR Observations
  8. Swift-BAT triggered on a posible CR Shower or possible GRB
  9. GRB 051012: Swift-BAT detection of burst yesterday
  10. GRB 050922B: optical limit
  11. GRB 050906: Possible X-ray Counterpart
  12. GRB 050906: MARGE Optical Limits
  13. GRB 050824: MDM Observations
  14. GRB050824: First 2 hours of power low optical decay?
  15. GRB050824: MASTER final analysis of the OT observations
  16. GRB050822: Swift/UVOT upper limits
  17. GRB050813: Maidanak I-band observations
  18. GRB 050822: Swift detection of a long burst
  19. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  20. GRB050803: CrAO optical observations, no OT candidate
  21. GRB 050805b: OHP optical limits
  22. GRB 050803: Magellan Observations
  23. GRB 050803: early Swift XRT analysis results
  24. GRB 050730: OHP optical observations
  25. GRB 050802: early Swift XRT analysis results
  26. GRB 050802: Swift/UVOT observations
  27. GRB 050802: XRT position
  28. Swift-BAT trigger 147918 is not a real GRB
  29. Swift BAT Trigger 146986 is SWIFT J1753.5-0127
  30. GRB050716, optical observation
  31. GRB 050713, R-band observations at NOT
  32. GRB050607: prompt REM observations
  33. GRB050525: Super-LOTIS observations
  34. GRB 050525: Optical observation
  35. XRF050522: NIR observations of XRT candidate
  36. XRF 050522: Swift XRT refined analysis
  37. GRB050502b: Early Observation
  38. GRB 050505, early TAROT observation
  39. GRB050509a: Swift UVOT observations
  40. GRB 050509a: Swift XRT Position
  41. Swift Detection of the Burst GRB050509
  42. GRB 050505: Keck I-band Magnitude
  43. GRB 050505: early time observations
  44. GRB (?) 050504: IR Observations, Intriguing Source
  45. GRB050326: optical limit
  46. Swift Detection of GRB 050319
  47. RXTE Observations of GRB050318
  48. GRB050309: CONCAM pre-trigger and trigger coincident optical
  49. GRB050215b: Faulkes North and SDSS limits on UKIRT candidate
  50. GRB 050219b: Swift XRT Position
  51. GRB050215b: Swift UVOT Detection of Afterglow Emission
  52. GRB 050215b: XRT confirmation of IR afterglow candidate
  53. GRB 050215B: candidate afterglow
  54. GRB 050215B: UKIRT K-band imaging
  55. GRB 050215b: Swift XRT Observations
  56. GRB050126: MASTER optical limit for KECK OT
  57. GRB050126: MASTER optical observations
  58. GRB050117: Palomar WIRC Ks-band observations
  59. GRB 041217: Optical observations
  60. GRB041226: ROTSE-III Optical Observations
  61. GRB041218: Continued P60 Optical Observations
  62. GRB 041218: Optical observations
  63. GRB041211,optical observation
  64. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  65. SGR 1806-20 still active
  66. GRB040924,optical observation
  67. IBAS GRB Alerts 1978-1980
  68. GRB040903 - A XRF?
  69. XRF040812: GMRT observations
  70. GRB 040812: Optical counterparts of CXO sources
  71. GRB 040812: Keck and LCO optical observations
  72. GRB 040812: Keck and LCO observations
  73. GRB040624: optical monitoring at TNG
  74. XRF040701: Second-Epoch Chandra Observations
  75. XRF040701: VLA Observations
  76. XRF040701: First-Epoch Chandra Observations
  77. IPN Summary of SGR1806-20 Activity in 2004
  78. MASTER: HETE Alert 3274 optical observation
  79. GRB040511: Candidate optical/NIR afterglow
  80. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  81. GRB 040228 (=H3066?,=H3067?): A Long GRB Localized by the HETE-2 WXM
  82. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  83. GRB040106: refined X-ray transient position
  84. GRB040106, Radio Observations
  85. GRB040106, likely optical afterglow
  86. GRB 040106: Optical observations
  87. XMM-Newton observation of GRB040106
  88. GRB 040106 : Planned XMM-Newton observation
  89. GRB 040106 : a long GRB detected with INTEGRAL
  90. GRB031220: Palomar Observations
  91. GRB 031203: IR NTTobservations do not confirm REM detection
  92. SN 2003jd (SN/GRB?) -- X-ray Observations
  93. IPN triangulation of GRB031016 (two large error boxes)
  94. XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
  95. IPN triangulation of GRB030921 (large error box)
  96. IPN triangulation of GRB030806 (large burst; large error box)
  97. XRF030723, ROTSE-III Early Observations
  98. XRF030723, optical observations
  99. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  100. IPN triangulation of GRB030715 (two large error boxes)

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