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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"

24887 results found.

  1. GRB 031203: Apparent Spectral Break
  2. GRB031203: Planned XMM-Newton observation II
  3. GRB 031203: IR REM Observations
  4. GRB031203: Optical Observations
  5. GRB 031203 XMM-Newton observation
  6. GRB031203: Planned XMM-Newton observation
  7. GRB 031203: further analysis of INTEGRAL data
  8. GRB 030329: Planned XMM-Newton Observation
  9. GRB 031111B (= H2925) : Kyoto Optical Observation
  10. IPN triangulation of GRB031114 (large error box)
  11. GRB 031111, optical observations
  12. GRB031026: 1.2mm upper limit with MAMBO at the IRAM 30m
  13. GRB030929/SN2003jd association unlikely based on IPN localiztion
  14. IPN triangulation of GRB031027 (small error box)
  15. Lulin optical follow-up observations of GRB031026
  16. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  17. IPN triangulation of GRB031024 (single error box)
  18. IPN triangulation of GRB031024 (annulus)
  19. IPN triangulation of GRB031020 (large error box)
  20. XRF 030824: additional observations at CFHT
  21. SGR1806-20 bursts on 031008. Helicon detection and small error box.
  22. XRF 030723: Subaru Optical Observations
  23. XRF 030824: Early follow-up observation at Kiso observatory
  24. XRF 030824: observations at CFHT
  25. IPN triangulation of GRB030922B (large error box)
  26. XRF 030723: Detection of the likely host galaxy
  27. XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
  28. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  29. IPN triangulation of GRB030921 (large error box)
  30. IPN triangulation of GRB030919 (large error box)
  31. GRB030913: Subaru Optical Observations
  32. GRB 030913, optical candidate
  33. GRB 030913, BOOTES observations
  34. IPN triangulation of GRB030916 (possible short/hard GRB; large error box)
  35. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  36. XRF 020427: Gemini-South Spectroscopic Observations of the Host
  37. XRF030824: Optical observations
  38. IPN triangulation of GRB030903 (large error box)
  39. IPN triangulation of GRB030827 (large error box)
  40. GRB030823: optical observations
  41. GRB030823: optical observation at Tokyo Tech
  42. Lulin follow-up observations of GRB030823
  43. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  44. IPN detection of continued activity from SGR1806-20
  45. GRB 030817 = H2808 TAROT optical observations
  46. SGR 1808-20 (=H2802): A Possible new SGR
  47. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  48. XRF 030723: Detection of a rebrightening in the optical afterglow
  49. XRF030723, BVRcIc field photometry update
  50. IPN triangulation of GRB030801 (large error box)
  51. GRB021206 optical counterpart upper limit
  52. IPN triangulation of GRB030726 (large error box)
  53. IPN triangulation of GRB030721 (large error box)
  54. XRF030723 Radio Observations
  55. XRF 030723: confirmation of fading optical counterpart
  56. XRF030723(=H2777): Chandra Observations
  57. GRB030723: Upper limits from historical observations
  58. XRF030723: Palomar observations and proposed counterpart
  59. GRB030725 (=H2779): A Bright GRB Localized by HETE
  60. XRF030723 (= H2777): Chandra Observations Scheduled
  61. XRF030723, BVRcIc field photometry correction
  62. XRF030723, ROTSE-III Early Observations
  63. XRF030723, BVRcIc field photometry
  64. XRF 030723, optical observations
  65. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  66. Konus-Wind detection of the bursts from SGR1806-20 region
  67. SGR 1806-20, submm observations
  68. RXTE PCA Observations of SGR1806-20 Region
  69. IPN triangulation of GRB030714 (two large error boxes)
  70. IPN triangulation of GRB030715 (two large error boxes)
  71. GRB030706 triangulation (single large error box)
  72. GRB030329, optical observation in May
  73. IPN triangulation of GRB030626 (single large error box)
  74. IPN triangulation of GRB030626 (two large error boxes)
  75. GRB030329: second XMM-Newton observation
  76. GRB030329 -- RATAN-600 data in April-May
  77. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  78. IPN triangulation of GRB030606 (two alternate error boxes)
  79. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  80. GRB 030528: tentative NIR counterpart
  81. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  82. GRB030528, BVRI field photometry
  83. GRB030329, SPM optical observations
  84. GRB030528: Chandra TOO Planned
  85. GRB030528(=H2724): Revised SXC Localization
  86. GRB 030528 Bisei optical observation
  87. GRB030528 (H2724): A long GRB localized by HETE
  88. GRB 030329: Correction to GCN 2254
  89. GRB 030329: Optical Observations
  90. GRB 030528 (=H2724) Kyoto optical observation
  91. GRB 030416: Optical Observations
  92. GRB 030329 Optical Observations
  93. GRB030329: XMM-Newton observation
  94. GRB 021004: HST observations
  95. GRB030324: Further Observations of the Candidate Optical Afterglow
  96. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  97. IPN triangulation of GRB030519B=H2716 (small error box)
  98. HETE GRB030329, correction to Rc Observations in Loiano
  99. GRB 030329: Optical limit (contemporaneous imaging)
  100. IPN triangulation of GRB030509 (small errror box)

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