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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"

3136 results found.

  1. GRB 050401: Prompt XRT position
  2. Refined Swift XRT positions for GRB050315, GRB050318 and GRB050319
  3. GRB050315: Radio afterglow
  4. GRB 050315: Optical afterglow identification
  5. GRB 050315: Swift XRT Position
  6. Swift-BAT detection of GRB 050315
  7. GRB050309: CONCAM pre-trigger and trigger coincident optical
  8. Swift trigger 107518: optical observation
  9. GRB 050306: TAROT optical observations
  10. GRB 050215b: XRT confirmation of IR afterglow candidate
  11. GRB 050215b: Swift XRT Source Variability
  12. GRB050128,optical observations
  13. GRB 050126: A NIR afterglow candidate in the revised XRT error circle
  14. GRB050126: Updated Swift XRT Position
  15. GRB050126: MASTER optical limit for KECK OT
  16. GRB050126: MASTER optical observations
  17. GRB 050126: Detection of NIR afterglow with Keck/NIRC
  18. GRB 050126: Prompt XRT detection and localization
  19. GRB 050124, SMARTS optical/IR observations
  20. GRB 050124: NIR Candidates from Keck/NIRC
  21. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  22. GRB041219; RXTE ASM Observations
  23. GRB 041219 ,optical observation
  24. Swift-BAT detection of the bright long burst GRB041219
  25. GRB041217: The First GRB Located On-Board Swift
  26. GRB 041211: Infrared Observations
  27. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  28. Triangulation of short GRB 041116 (large error box)
  29. GRB 041006 (=H3570): An X-Ray Rich GRB Localized in Real Time by HETE
  30. GRB040924: Optical afterglow properties
  31. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  32. GRB040912 : Kiso Optical follow-up observation
  33. GRB040823,optical observation
  34. GRB 040812: Optical counterparts of CXO sources
  35. CXO observation of GRB 040812
  36. GRB 040812: a long GRB detected by INTEGRAL
  37. IPN Summary of SGR1806-20 Activity in 2004
  38. Activivty of SGR 1806-20
  39. IPN triangulation of GRB040228 (H3066, H3067)
  40. XMM-Newton Images of GRB 040223
  41. IPN triangulation of GRB031027 (small error box)
  42. Lulin optical follow-up observations of GRB031026
  43. IPN triangulation of GRB030926 (short/hard; large error box)
  44. IPN triangulation of GRB030903 (large error box)
  45. IPN triangulation of GRB030801 (large error box)
  46. XRF030723(=H2777): Chandra Observations
  47. XRF030723: Palomar observations and proposed counterpart
  48. XRF 030723, optical observations
  49. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  50. IPN triangulation of GRB030715 (two large error boxes)
  51. GRB 021206, Radio afterglow candidate
  52. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  53. GRB 030329 Optical Observations
  54. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  55. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  56. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  57. IPN triangulation of GRB030422 (two large error boxes)
  58. ROTSE-III prompt optical detections of GRB 030418
  59. GRB030329: Kiso B and R band observations
  60. GRB 030329: SARA Optical Observations
  61. GRB030329: final R-band light curve by MASTER
  62. GRB030329, optical observation
  63. GRB 030329, BRI photometry
  64. Further AAVSO V,B,R observations of GRB030329
  65. GRB 030329: Additional Mt. Laguna Optical Observations
  66. GRB 030329: optical observations
  67. GRB 030329, optical photometry
  68. GRB030329 - Light curve flattening
  69. GRB030329 - near contemporaneous optical limits from CONCAM
  70. GRB030329, SPM optical observations
  71. GRB 030328 Optical Observations
  72. GRB030328: Decay index
  73. Possible GRB030323 localized by INTEGRAL
  74. IPN triangulation of GRB030325 (single small error box)
  75. IPN triangulation of GRB030325 (two small error boxes)
  76. GRB030323 (=H2640): A Faint, Long GRB Localized by the HETE WXM and SXC
  77. GRB 030320: Optical Observations
  78. IPN triangulation of GRB030320 (small error box)
  79. GRB030227 localized by INTEGRAL
  80. GRB030131: Optical limits for corrected position
  81. GRB 030131: afterglow candidate
  82. GRB030131: Optical limit
  83. GRB030115: Optical Observations, Swiss Telescope at La Silla (ESO, Chile)
  84. GRB021211 (=H2493): A Bright, Long GRB Localized by HETE-2 in Near-Real Time
  85. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  86. IPN triangulation of GRB021027 (single large error box)
  87. GRB 021016, optical observations
  88. GRB021004: Optical Observations
  89. GRB021004: BVRc photometry
  90. GRB 021004: Optical observations at RIKEN
  91. GRB 021004: Optical Observations
  92. GRB 021004: Optical Observations
  93. GRB 021004, SPM optical observations
  94. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  95. GRB020813(=H2262): A Long, Bright Burst Localized by HETE in Near-Real Time
  96. IPN triangulation of GRB020708
  97. IPN triangulation of GRB020708
  98. GRB 020625, optical observations
  99. GRB 020317 : KISO Optical Observations
  100. GRB 020305: Candidate optical afterglow

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