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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"

19548 results found.

  1. GRB050525A,optical observation
  2. GRB050525: Super-LOTIS observations
  3. GRB050306: optical afterglow not confirmed
  4. GRB 050525: BART optical observation
  5. GRB 050525A: BOOTES simultaneous optical observations
  6. GRB050525: Optical observations
  7. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  8. GRB 050525: TAROT observations of the early afterglow
  9. INTEGRAL detection of GRB 050525
  10. GRB 050525, infrared observations
  11. GRB 050525: Optical observation
  12. GRB 050525: observatons of the optical afterglow
  13. GRB050525: ROTSE-III Refined Analysis
  14. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  15. XRF050522: Radio Observations
  16. Swift/UVOT observation of XRF 050522
  17. GRB 050509A: Further I-band imaging
  18. GRB050522,optical observation
  19. GRB050520,optical observation
  20. XRF 050522: Continued NIR P200 Monitoring
  21. RBO Observations of GRB050522
  22. Recent GRB BVRcIc field photometry
  23. GRB050520: Radio Observations
  24. XRF 050522: Swift XRT observation
  25. XRF050522, BVRcIc field photometry
  26. XRF050522: Optical Observations
  27. XRF050522: Near-infrared Observations
  28. GRB 050520: VLT/ULTRACAM observations
  29. Swift UVOT Observations of GRB 050520
  30. XRF050509c: Radio Observations
  31. RBO Observations of GRB050520
  32. GRB 050520: P200 Observations
  33. GRB050520: Liverpool Telescope follow-up
  34. RBO Observations of GRB050520
  35. GRB 050520: TAROT optical limit
  36. GRB 050520: VLT/ULTRACAM observations
  37. GRB050502b: Early Observation
  38. GRB050509b, Bok telescope B-band imaging
  39. GRB050509b, SDSS pre-burst observations
  40. GRB 050509b: Keck/Chandra Cross-Correlation
  41. GRB 050509b: Keck/Chandra Cross-Correlation
  42. Chandra observation of GRB 050509b
  43. GRB 050509b Milagro GeV/TeV Observations
  44. GRB050509B: Optical observations at the Very Large Telescope
  45. GRB 050509b: No Optical Variability in XRT Error Circle
  46. GRB 050509c: ROTSE-III Optical Limits
  47. GRB 050505, early TAROT observation
  48. GRB050509c: REM NIR and Optical observations
  49. GRB 050505: SARA Observations
  50. GRB 050509B: Swift/XRT refined analysis
  51. GRB 050509A: Optical observations
  52. GRB050509b: Radio Observations
  53. GRB 050509b: Swift-BAT refined analysis of the short hard burst
  54. Swift Detection of GRB050509b: A short duration burst
  55. Swift Detection of the Burst GRB050509
  56. GRB 050505, simultaneous optical observation
  57. GRB050505: AAVSO observations
  58. GRB050416A : 1 GHz limit from GMRT
  59. GRB050505: Optical Afterglow Candidate
  60. GRB 050416b:Swift XRT afterglow upper limits
  61. GRB 050416b:Swift XRT afterglow upper limits
  62. GRB050502b: Afterglow Confirmation: Correction to OT Coordinates
  63. GRB050502b: Afterglow Confirmation
  64. GRB050502: P200 Observations (Correction)
  65. GRB050502: P200 Observations
  66. Swift UVOT observation of GRB 050504
  67. GRB050504: P60 Observations
  68. GRB 050504: A long GRB detected with INTEGRAL
  69. GRB (?) 050504: IR Observations, Intriguing Source
  70. GRB 050502b, Optical observations
  71. GRB050502a: P60 Observations (Correction)
  72. GRB050502a: P60 Observations
  73. GRB050502B Swift-BAT refined analysis
  74. Swift Detection of the Bright Burst GRB050502b
  75. GRB 050502: ROTSE-III Detection of Possible Counterpart
  76. Swift/BAT possible detection of a weak burst GRB050430
  77. GRB050416a: Radio Detection
  78. Swift Detection of GRB 050422
  79. GRB 050421: SLOTIS observations
  80. GRB 050421: Further Analysis of IR imaging
  81. GRB050421: Radio Observations
  82. GRB050421: Radio Observations
  83. GRB 050421: IR Observations
  84. GRB050421
  85. GRB 050421: NIR observations
  86. GRB050421: P60 Observations
  87. GRB 050421: BOOTES-2 simultaneous optical observations
  88. GRB 050416b: Tentative Swift XRT Position
  89. GRB 050315: potential host galaxy
  90. GRB050326: analysis of the XMM-Newton observation
  91. GRB050418: Null Optical Observations
  92. GRB050416A, optical observations
  93. GRB 050418: Swift-BAT refined analysis
  94. GRB 050416: Mitsume optical observation
  95. GRB050416B: IR observations
  96. GRB050412: Radio Observations
  97. GRB 050416: Swift/UVOT detection of afterglow emission
  98. GRB 050416,optical observation
  99. GRB050416: P200 NIR Observations
  100. GRB 050416: Radio observations

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