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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"

4953 results found.

  1. GRB 050319: Swift-UVOT detection of the afterglow
  2. GRB050319,optical observation
  3. Swift Detection of GRB 050319
  4. GRB050223: analysis of the XMM-Newton observation
  5. GRB 050315, SMARTS optical/IR afterglow observations
  6. GRB050306: 250 GHz upper limit with MAMBO at the IRAM 30m
  7. GRB050309: CONCAM pre-trigger and trigger coincident optical
  8. GRB 050306: optical afterglow
  9. GRB 050306: Confirmation of X-ray afterglow
  10. Swift-BAT trigger 107873 (GRB050309): possible X-ray counterparts
  11. GRB 050306: Possible X-ray Afterglow Position from the Swift
  12. PROMPT VRcIc Observations of GRB 050223
  13. GRB 050223 Swift/BAT detection of a burst
  14. GRB 050223: Swift XRT Position
  15. GRB 050215b: XRT confirmation of IR afterglow candidate
  16. GRB 050215b: Swift XRT Source Variability
  17. GRB 050209 Optical observations
  18. GRB041219: P60 Optical Observations
  19. GRB 041218: Optical observations
  20. GRB 041016: Optical limits
  21. SGR 1806-20 still active
  22. GRB040924: Optical afterglow properties
  23. GRB040916 optical limits 17 min after GRB
  24. GRB040916: Optical observations
  25. GRB/XRF040912,optical observations
  26. An intense burst from SGR1806-20
  27. IBAS GRB Alerts 1978-1980
  28. GRB040903 - A XRF?
  29. MASTER: GRB040827 possible OT
  30. GRB 040827 : Planned XMM-Newton observation
  31. GRB 040827 - A long GRB detected by INTEGRAL
  32. XRF040701: VLA Observations
  33. GRB040709 J,H-band observations
  34. IPN Summary of SGR1806-20 Activity in 2004
  35. GRB 040423 (=H3175): A Long GRB Localized by HETE
  36. GRB 040319 (=H3128): An X-Ray-Rich GRB Localized by the HETE-2 WXM and SXC
  37. GRB031220: Palomar Observations
  38. GRB 031220 : Kyoto Optical Observation
  39. GRB 031220: Optical observation at Tokyo Tech
  40. GRB 031203: Discovery of a dust echo
  41. GRB031203: K' Photometry of the likely GRB host
  42. IPN triangulation of GRB031111 (=H2924): small error box
  43. Lulin optical follow-up observations of GRB031026
  44. GRB 031026: Ic Observations
  45. IPN triangulation of GRB030919 (large error box)
  46. GRB030913: AAVSO optical observations
  47. 030813 SGR event (Konus-Wind observation)
  48. SGR 1808-20 (=H2802): A Possible new SGR
  49. XRF030723(=H2777): Chandra Observations
  50. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  51. GRB 021206, Radio afterglow candidate
  52. GRB030329, Optical observations
  53. GRB 021004: HST observations
  54. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  55. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  56. GRB030329: 444 AAVSO Measurements
  57. IPN triangulation of GRB050403 (small error box)
  58. GRB030329: RTT150 optical observations
  59. GRB030329: More AAVSO VR obs
  60. GRB 030329, BVRI photometry
  61. GRB030329: final R-band light curve by MASTER
  62. GRB 030329, BRI photometry
  63. GRB 030329: Additional Mt. Laguna Optical Observations
  64. GRB 030329: optical observations
  65. GRB 030329: OT candidate
  66. GRB030323: V, R, I photometry
  67. GRB 030227: Optical limit at RIKEN
  68. GRB 030227: Kyoto optical observation
  69. Possible GRB 20030109 seen by SPI ACS
  70. GRB021211: APO optical observations
  71. GRB021211: Optical observations
  72. GRB021113 (=H2449): A Long GRB Localized by HETE
  73. GRB021104: Optical observations
  74. GRB021104: optical observations
  75. GRB021104: possible optical afterglow
  76. IPN triangulation of GRB021023 (small error boc)
  77. GRB021016(=H2397): A Long GRB Localized by HETE
  78. GRB021004: Optical Observations
  79. GRB021004: Optical Observations
  80. GRB021004: BVRc photometry
  81. GRB021004: not fading anymore?
  82. GRB 021004: Optical Photometry at 2.5 Days
  83. GRB 021004: Optical observations at RIKEN
  84. GRB 021004: Optical Observations
  85. GRB 021004, optical observations
  86. GRB 021004: Optical Observations
  87. GRB 021004, SPM optical observations
  88. GRB 021004, optical observations
  89. INTEGRAL GRBs added to GCN
  90. GRB 020812 optical observation
  91. IPN triangulation of GRB020714
  92. IPN triangulation of GRB020714
  93. GRB020531(=H2042): Optical Observations
  94. XRF020427: Chandra Identification of a Likely X-ray Counterpart
  95. GRB/XRF 020427, Radio Observations
  96. GRB011212: Optical Observations
  97. GRB 020322: Optical Observations
  98. GRB 020322 optical observation
  99. GRB 020317 : KISO Optical Observations
  100. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB

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