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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"

26364 results found.

  1. XRF 030824: observations at CFHT
  2. IPN triangulation of GRB030922B (large error box)
  3. XRF 030723: Detection of the likely host galaxy
  4. XRF030824 (=H2821): An X-Ray Flash Localized by the HETE WXM
  5. XRF030823 (=H2818): An X-Ray Flash Localized by the HETE WXM and SXC
  6. IPN triangulation of GRB030921 (large error box)
  7. IPN triangulation of GRB030919 (large error box)
  8. GRB030913: Subaru Optical Observations
  9. GRB 030913, optical candidate
  10. GRB 030913, BOOTES observations
  11. IPN triangulation of GRB030916 (possible short/hard GRB; large error box)
  12. GRB030913: wide field imaging (7 sq.deg) of the error box by MASTER
  13. XRF 020427: Gemini-South Spectroscopic Observations of the Host
  14. XRF030824: Optical observations
  15. IPN triangulation of GRB030903 (large error box)
  16. IPN triangulation of GRB030827 (large error box)
  17. GRB030823: optical observations
  18. GRB030823: optical observation at Tokyo Tech
  19. Lulin follow-up observations of GRB030823
  20. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  21. IPN detection of continued activity from SGR1806-20
  22. GRB 030817 = H2808 TAROT optical observations
  23. SGR 1808-20 (=H2802): A Possible new SGR
  24. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  25. XRF 030723: Detection of a rebrightening in the optical afterglow
  26. XRF030723, BVRcIc field photometry update
  27. IPN triangulation of GRB030801 (large error box)
  28. GRB021206 optical counterpart upper limit
  29. IPN triangulation of GRB030726 (large error box)
  30. IPN triangulation of GRB030721 (large error box)
  31. XRF030723 Radio Observations
  32. XRF 030723: confirmation of fading optical counterpart
  33. XRF030723(=H2777): Chandra Observations
  34. GRB030723: Upper limits from historical observations
  35. XRF030723: Palomar observations and proposed counterpart
  36. GRB030725 (=H2779): A Bright GRB Localized by HETE
  37. XRF030723 (= H2777): Chandra Observations Scheduled
  38. XRF030723, BVRcIc field photometry correction
  39. XRF030723, ROTSE-III Early Observations
  40. XRF030723, BVRcIc field photometry
  41. XRF 030723, optical observations
  42. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  43. Konus-Wind detection of the bursts from SGR1806-20 region
  44. SGR 1806-20, submm observations
  45. RXTE PCA Observations of SGR1806-20 Region
  46. IPN triangulation of GRB030714 (two large error boxes)
  47. IPN triangulation of GRB030715 (two large error boxes)
  48. GRB030706 triangulation (single large error box)
  49. GRB030329, optical observation in May
  50. IPN triangulation of GRB030626 (single large error box)
  51. IPN triangulation of GRB030626 (two large error boxes)
  52. GRB030329: second XMM-Newton observation
  53. GRB030329 -- RATAN-600 data in April-May
  54. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  55. IPN triangulation of GRB030606 (two alternate error boxes)
  56. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  57. GRB 030528: tentative NIR counterpart
  58. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  59. GRB030528, BVRI field photometry
  60. GRB030329, SPM optical observations
  61. GRB030528: Chandra TOO Planned
  62. GRB030528(=H2724): Revised SXC Localization
  63. GRB 030528 Bisei optical observation
  64. GRB030528 (H2724): A long GRB localized by HETE
  65. GRB 030329: Correction to GCN 2254
  66. GRB 030329: Optical Observations
  67. GRB 030528 (=H2724) Kyoto optical observation
  68. GRB 030416: Optical Observations
  69. GRB 030329 Optical Observations
  70. GRB030329: XMM-Newton observation
  71. GRB 021004: HST observations
  72. GRB030324: Further Observations of the Candidate Optical Afterglow
  73. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  74. IPN triangulation of GRB030519B=H2716 (small error box)
  75. HETE GRB030329, correction to Rc Observations in Loiano
  76. GRB 030329: Optical limit (contemporaneous imaging)
  77. IPN triangulation of GRB030509 (small errror box)
  78. GRB030329, BVRI photometry
  79. GRB030429, refiend optical brightness
  80. GRB 030329: Optical limit (contemporaneous photography)
  81. GRB030418, BVRcIc field photometry
  82. GRB030429, BVRcIc field photometry
  83. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  84. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  85. GRB030329: RTT150 optical observations and upper limit for a host
  86. GRB030501, optical observation
  87. GRB030501 triangulation (correction to GCN 2194)
  88. GRB030329: RTT150 optical observations and upper limit for a host
  89. GRB 030429: redshift from VLT spectroscopy
  90. GRB030501B triangulation (single error box)
  91. GRB 030329, BVRI photometry
  92. GRB030429: Optical Observations
  93. GRB030501: TAROT candidate afterglow present in archival images
  94. GRB 030429: confirmation of afterglow candidate
  95. GRB 030329 Oprical observations in Rozhen observatory
  96. SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
  97. IPN triangulation of GRB030425 (single error box)
  98. GRB 030329, the review of the sky area in plate archive (1950-1998)
  99. GRB 030329: optical spectropolarimetry at VLT
  100. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst

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