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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"
  1. GRB 030528: Optical Observations
  2. IPN triangulation of GRB030605 (annulus)
  3. GRB 030528: tentative NIR counterpart
  4. GRB 030528, radio observations
  5. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  6. GRB030329, further radio observations at GMRT
  7. GRB030528, BVRI field photometry
  8. IPN triangulation of GRB030601 (annulus)
  9. GRB030329, SPM optical observations
  10. GRB030528: Chandra TOO Planned
  11. GRB 030519B: optical observations.
  12. MASTER: optical observation GRB030601
  13. GRB030528(=H2724): Revised SXC Localization
  14. GRB 030329: optical observations
  15. GRB 030329/SN 2003dh: Jitter Episode
  16. GRB 030528, Teramo optical observation
  17. GRB 030528 Bisei optical observation
  18. GRB030528 (H2724): A long GRB localized by HETE
  19. GRB 030329: Correction to GCN 2254
  20. GRB 030329: Optical Observations
  21. GRB 030528: Optical observations at RIKEN
  22. GRB 030528 (=H2724) Kyoto optical observation
  23. IPN triangulation of GRB030523B (annulus)
  24. GRB 030416: Optical Observations
  25. GRB 030329: Planned XMM-Newton Observation
  26. IPN triangulation of GRB030523 (annulus)
  27. GRB 030329: optical photometry at various french observatories
  28. GRB 030329: optical photometry at Belesta observatory (France)
  29. GRB030329, Optical observations
  30. GRB 030329/SN 2003dh: Possible increase in brightness
  31. GRB 030329: HST ACS Observations of the Host
  32. GRB 030329 Optical Observations
  33. GRB030329: XMM-Newton observation
  34. GRB 021004: HST observations
  35. GRB030324: Further Observations of the Candidate Optical Afterglow
  36. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  37. IPN triangulation of GRB030519B=H2716 (small error box)
  38. GRB 030418: Second Epoch Optical Observations with Magellan
  39. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  40. IPN triangulation of GRB030519 (annulus)
  41. IPN triangulation of GRB030518C (annulus)
  42. IPN triangulation of GRB030518B (annulus)
  43. IPN triangulation of GRB030518A (annulus)
  44. IPN triangulation of GRB030514 (annulus)
  45. HETE GRB030329, correction to Rc Observations in Loiano
  46. IPN triangulation of GRB030513 (annulus)
  47. IPN triangulation of GRB030509B (annulus)
  48. GRB 030329: Optical limit (contemporaneous imaging)
  49. GRB 030501: final TAROT limits
  50. IPN triangulation of GRB030509 (small errror box)
  51. IPN triangulation of GRB030509 - correction
  52. IPN triangulation of GRB030509 (single error box)
  53. GRB030329: RTT150 optical observations
  54. GRB030329, BVRI photometry
  55. GRB030429, refiend optical brightness
  56. GRB 030329: Optical limit (contemporaneous photography)
  57. GRB030418, BVRcIc field photometry
  58. GRB 030429: Redshift of neighbor galaxy
  59. GRB030429, BVRcIc field photometry
  60. GRB030429: RTT150 optical obs., correction to GCN 2208
  61. GRB 030329: High-Resolution Spectroscopy of the Host
  62. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  63. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  64. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  65. GRB030429: RTT150 optical observations, a possible host galaxy
  66. IPN triangulation of GRB030506 (annulus)
  67. IPN triangulation of GRB030505B (large error box)
  68. IPN triangulation of GRB030505A (annulus)
  69. GRB030329: RTT150 optical observations and upper limit for a host
  70. GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
  71. GRB030501, optical observation
  72. GRB030501 observation report
  73. GRB030501C triangulation (annulus)
  74. GRB030501 triangulation (correction to GCN 2194)
  75. GRB030329: RTT150 optical observations and upper limit for a host
  76. GRB 030429: Radio Observations
  77. GRB 030429: redshift from VLT spectroscopy
  78. GRB 030429: IR photometry with IRSF/SIRIUS
  79. GRB030501B triangulation (single error box)
  80. GRB 030329 Optical Observations
  81. GRB030328, optical observation
  82. GRB 030329, BVRI photometry
  83. GRB030429: Optical Observations
  84. GRB030501: TAROT candidate afterglow present in archival images
  85. GRB 030501: TAROT possible candidate counterpart
  86. IPN triangulation of GRB030501 (IBIS event; annulus)
  87. IPN triangulation of GRB030501B (annulus)
  88. GRB 030429: confirmation of afterglow candidate
  89. GRB030429, possible optical counterpart
  90. GRB030501 localized by INTEGRAL
  91. GRB030425: CrAO optical observation
  92. IPN triangulation of GRB030429 (annulus)
  93. IPN triangulation of GRB030428 (two large error boxes)
  94. GRB 030329 Oprical observations in Rozhen observatory
  95. GRB 030429: ROTSE-III observations
  96. GRB 030324: Radio Observations
  97. GRB030329 observed as a sudden ionospheric disturbance (SID)
  98. IPN triangulation of GRB030426 (annulus)
  99. SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
  100. IPN triangulation of GRB030425 (single error box)

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