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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"

27135 results found.

  1. GRB010324, field photometry
  2. GRB010326B, field photometry
  3. GRB010326, field photometry
  4. GRB010220, field photometry
  5. Further Optical Observations of GRB 010324
  6. GRB010222, CXO X-ray observations
  7. GRB010324, optical observations
  8. GRB010326B: Localization by HETE (2nd GRB for this date)
  9. GRB 010326 optical observations
  10. GRB010326: Refined Localization by HETE
  11. GRB010326: Localization by HETE
  12. Optical Observations of GRB 010324
  13. GRB010222, late-time optical observation
  14. Support extension to the BeppoSAX mission
  15. GRB 010222 - HEGRA GeV/TeV Observations
  16. GRB010222: Chandra X-ray Observatory Observation
  17. GRB010222: Sub-millimeter vanishing act
  18. GRB010222 - Optical observation
  19. GRB 010222, Optical Observations
  20. GRB010222 - Optical observation
  21. GRB 010222: High-Resolution Keck Spectroscopy
  22. GRB 010214, I-band data
  23. GRB 010222
  24. GRB010222 further R-band photometry
  25. GRB010222: R-band data
  26. GRB 010222: Keck Spectroscopy
  27. GRB010214, field photometry
  28. GRB010222, field photometry
  29. GRB010222 further R-band photometry
  30. GRB010222, possible increase of optical decay slope
  31. GRB 010222 Kyoto optical observation
  32. GRB010222 R-BAND OBSERVATION
  33. GRB010214 follow-up from Hanle
  34. GRB 010222: Near-IR Observations
  35. GRB 010222: Optical Observations
  36. GRB010222: Optical decay slope
  37. GRB 010214, Optical Observations
  38. GRB010222, radio observations
  39. GRB010222, optical observations
  40. GRB010222: BeppoSAX/NFI Observations
  41. GRB010214B,Gamma Ray Observations
  42. GRB 010220, simultaneous optical observations
  43. GRB010220: BeppoSAX WFC and GRBM preliminary data
  44. GRB010214, candidate optical afterglow
  45. GRB010214, optical observations
  46. GRB010214: BeppoSAX WFC and GRBM preliminary data
  47. GRB 010214: X-Ray afterglow
  48. GRB 010214 optical observation
  49. GRB010213, Radio Observations
  50. J-Band Observation of GRB 010214.
  51. GRB010213, Near-IR observations
  52. Possible InfraRed Transient of GRB 010214.
  53. GRB 010214, optical observations
  54. GRB010213 detected by HETE
  55. IPN Status Report
  56. HETE Status
  57. IPN/RXTE TRIANGULATION OF GRB010126
  58. GRB010126 Optical Observations
  59. IPN TRIANGULATION OF GRB010126
  60. Optical Observations of GRB 001018 at Keck
  61. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  62. Optical observations of GRB 001018 with JCAM
  63. IPN TRIANGULATION OF GRB010115
  64. IPN TRIANGULATION OF GRB010109
  65. IPN TRIANGULATION OF GRB010109
  66. IPN triangulation of GRB010104
  67. IPN triangulation of GRB010103
  68. H band observation of GRB 001212
  69. IPN triangulation of GRB001219
  70. GRB 001212 Optical Observation
  71. GRB 001212 Optical Observation
  72. GRB 001212 possible OA in 2MASS
  73. IPN triangulation of GRB001212
  74. Confirmation of IPN position for GRB001204
  75. IPN triangulation of GRB001204 (short/hard)
  76. GRB001120, optical observations
  77. WSRT 4.8 GHz observations of GRB001109
  78. IPN triangulation of GRB001120
  79. GRB 001109: deep JHK upper limits
  80. GRB 001109 X-ray afterglow with BeppoSAX
  81. CORRECTION to XMM-Newton observation of GRB001025
  82. GRB001109, Radio observations
  83. GRB001105 BVRI field photometry correction
  84. GRB001105, BVRI field photometry
  85. IPN TRIANGULATION OF GRB001105
  86. GRB 001025B, Optical obervations
  87. GRB 991208: HST Imaging of the Host Galaxy
  88. GRB 001025B, I-band observations
  89. XMM-Newton observation of GRB001025
  90. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  91. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  92. GRB001007: Optical observations
  93. ASM Localization of GRB 001025
  94. GRB001007, Radio observations
  95. GRB 001018, Possible Radio Afterglow
  96. GRB001018, Gamma Ray Observations
  97. IPN TRIANGULATION OF GRB001019
  98. IPN TRIANGULATION OF GRB001018
  99. IPN TRIANGULATION OF GRB 001017
  100. V,R,I band observations of GRB000926

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