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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"

3139 results found.

  1. GRB 050412: Swift XRT Position
  2. GRB 050408: Optical limit at 20 min after the burst
  3. Swift-BAT detection of GRB 050401
  4. GRB 050401: Prompt XRT position
  5. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  6. GRB050315: Radio afterglow
  7. GRB 050315: Optical afterglow identification
  8. GRB 050315: Swift XRT Position
  9. Swift-BAT detection of GRB 050315
  10. GRB050309: CONCAM pre-trigger and trigger coincident optical
  11. Swift trigger 107518: optical observation
  12. GRB 050306: TAROT optical observations
  13. GRB 050215b: XRT confirmation of IR afterglow candidate
  14. GRB 050215b: Swift XRT Source Variability
  15. GRB050128,optical observations
  16. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  17. GRB050126: Updated Swift XRT Position
  18. GRB050126: MASTER optical limit for KECK OT
  19. GRB050126: MASTER optical observations
  20. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  21. GRB 050126: Prompt XRT detection and localization
  22. GRB 050124, SMARTS optical/IR observations
  23. GRB 050124: NIR Candidates from Keck/NIRC
  24. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  25. GRB041219; RXTE ASM Observations
  26. GRB 041219 ,optical observation
  27. Swift-BAT detection of the bright long burst GRB041219
  28. GRB041217: The First GRB Located On-Board Swift
  29. GRB 041211: Infrared Observations
  30. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  31. Triangulation of short GRB 041116 (large error box)
  32. GRB 041006 (=H3570): An X-Ray Rich GRB Localized in Real Time by HETE
  33. GRB040924: Optical afterglow properties
  34. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  35. GRB040912 : Kiso Optical follow-up observation
  36. GRB040823,optical observation
  37. GRB 040812: Optical counterparts of CXO sources
  38. CXO observation of GRB 040812
  39. GRB 040812: a long GRB detected by INTEGRAL
  40. IPN Summary of SGR1806-20 Activity in 2004
  41. Activivty of SGR 1806-20
  42. IPN triangulation of GRB040228 (H3066, H3067)
  43. XMM-Newton Images of GRB 040223
  44. IPN triangulation of GRB031027 (small error box)
  45. Lulin optical follow-up observations of GRB031026
  46. IPN triangulation of GRB030926 (short/hard; large error box)
  47. IPN triangulation of GRB030903 (large error box)
  48. IPN triangulation of GRB030801 (large error box)
  49. XRF030723(=H2777): Chandra Observations
  50. XRF030723: Palomar observations and proposed counterpart
  51. XRF 030723, optical observations
  52. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  53. IPN triangulation of GRB030715 (two large error boxes)
  54. GRB 021206, Radio afterglow candidate
  55. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  56. GRB 030329 Optical Observations
  57. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  58. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  59. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  60. IPN triangulation of GRB030422 (two large error boxes)
  61. ROTSE-III prompt optical detections of GRB 030418
  62. GRB030329: Kiso B and R band observations
  63. GRB 030329: SARA Optical Observations
  64. GRB030329: final R-band light curve by MASTER
  65. GRB030329, optical observation
  66. GRB 030329, BRI photometry
  67. Further AAVSO V,B,R observations of GRB030329
  68. GRB 030329: Additional Mt. Laguna Optical Observations
  69. GRB 030329: optical observations
  70. GRB 030329, optical photometry
  71. GRB030329 - Light curve flattening
  72. GRB030329 - near contemporaneous optical limits from CONCAM
  73. GRB030329, SPM optical observations
  74. GRB 030328 Optical Observations
  75. GRB030328: Decay index
  76. Possible GRB030323 localized by INTEGRAL
  77. IPN triangulation of GRB030325 (single small error box)
  78. IPN triangulation of GRB030325 (two small error boxes)
  79. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  80. GRB 030320: Optical Observations
  81. IPN triangulation of GRB030320 (small error box)
  82. GRB030227 localized by INTEGRAL
  83. GRB030131: Optical limits for corrected position
  84. GRB 030131: afterglow candidate
  85. GRB030131: Optical limit
  86. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  87. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  88. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  89. IPN triangulation of GRB021027 (single large error box)
  90. GRB 021016, optical observations
  91. GRB021004: Optical Observations
  92. GRB021004: BVRc photometry
  93. GRB 021004: Optical observations at RIKEN
  94. GRB 021004: Optical Observations
  95. GRB 021004: Optical Observations
  96. GRB 021004, SPM optical observations
  97. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  98. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  99. IPN triangulation of GRB020708
  100. IPN triangulation of GRB020708

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