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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"

5845 results found.

  1. GRB 050306: Confirmation of X-ray afterglow
  2. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  3. GRB 050306: Possible X-ray Afterglow Position from the Swift
  4. PROMPT VRcIc Observations of GRB 050223
  5. GRB 050223 Swift/BAT detection of a burst
  6. GRB 050223: Swift XRT Position
  7. GRB 050215b: XRT confirmation of IR afterglow candidate
  8. GRB 050215b: Swift XRT Source Variability
  9. GRB 050209 Optical observations
  10. GRB041219: P60 Optical Observations
  11. GRB 041218: Optical observations
  12. GRB 041016: Optical limits
  13. SGR 1806-20 still active
  14. GRB040924: Optical afterglow properties
  15. GRB040916 optical limits 17 min after GRB
  16. GRB040916: Optical observations
  17. GRB/XRF040912,optical observations
  18. An intense burst from SGR1806-20
  19. IBAS GRB Alerts 1978-1980
  20. GRB040903 - A XRF?
  21. MASTER: GRB040827 possible OT
  22. GRB 040827 : Planned XMM-Newton observation
  23. GRB 040827 - A long GRB detected by INTEGRAL
  24. XRF040701: VLA Observations
  25. GRB040709 J,H-band observations
  26. IPN Summary of SGR1806-20 Activity in 2004
  27. GRB 040423 (=H3175): A Long GRB Localized by HETE
  28. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  29. GRB031220: Palomar Observations
  30. GRB 031220 : Kyoto Optical Observation
  31. GRB 031220: Optical observation at Tokyo Tech
  32. GRB 031203: Discovery of a dust echo
  33. GRB031203: K' Photometry of the likely GRB host
  34. IPN triangulation of GRB031111 (=H2924): small error box
  35. Lulin optical follow-up observations of GRB031026
  36. GRB 031026: Ic Observations
  37. IPN triangulation of GRB030919 (large error box)
  38. GRB030913: AAVSO optical observations
  39. 030813 SGR event (Konus-Wind observation)
  40. SGR 1808-20 (=H2802): A Possible new SGR
  41. XRF030723(=H2777): Chandra Observations
  42. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  43. GRB 021206, Radio afterglow candidate
  44. GRB030329, Optical observations
  45. GRB 021004: HST observations
  46. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  47. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  48. GRB030329: 444 AAVSO Measurements
  49. IPN triangulation of GRB050403 (small error box)
  50. GRB030329: RTT150 optical observations
  51. GRB030329: More AAVSO VR obs
  52. GRB 030329, BVRI photometry
  53. GRB030329: final R-band light curve by MASTER
  54. GRB 030329, BRI photometry
  55. GRB 030329: Additional Mt. Laguna Optical Observations
  56. GRB 030329: optical observations
  57. GRB 030329: OT candidate
  58. GRB030323: V, R, I photometry
  59. GRB 030227: Optical limit at RIKEN
  60. GRB 030227: Kyoto optical observation
  61. Possible GRB 20030109 seen by SPI ACS
  62. GRB021211: APO optical observations
  63. GRB021211: Optical observations
  64. GRB021113 (=H2449): A Long GRB Localized by HETE
  65. GRB021104: Optical observations
  66. GRB021104: optical observations
  67. GRB021104: possible optical afterglow
  68. IPN triangulation of GRB021023 (small error boc)
  69. GRB021016(=H2397): A Long GRB Localized by HETE
  70. GRB021004: Optical Observations
  71. GRB021004: Optical Observations
  72. GRB021004: BVRc photometry
  73. GRB021004: not fading anymore?
  74. GRB 021004: Optical Photometry at 2.5 Days
  75. GRB 021004: Optical observations at RIKEN
  76. GRB 021004: Optical Observations
  77. GRB 021004, optical observations
  78. GRB 021004: Optical Observations
  79. GRB 021004, SPM optical observations
  80. GRB 021004, optical observations
  81. INTEGRAL GRBs added to GCN
  82. GRB 020812 optical observation
  83. IPN triangulation of GRB020714
  84. IPN triangulation of GRB020714
  85. GRB020531(=H2042): Optical Observations
  86. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  87. GRB/XRF 020427, Radio Observations
  88. GRB011212: Optical Observations
  89. GRB 020322: Optical Observations
  90. GRB 020322 optical observation
  91. GRB 020317 : KISO Optical Observations
  92. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  93. RXTE Observations of SGR 1900+14
  94. IPN Upper Limits to a GRB Associated With SN2002ap
  95. GRB020124 BVRI field photometry
  96. GRB020127 Optical Observations
  97. GRB 020124 Optical Observations
  98. GRB011212: Optical observations at Gunma
  99. GRB011212: Optical observations
  100. GRB 011211, Optical Observations

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