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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"

44626 results found.

  1. GRB 030501: final TAROT limits
  2. IPN triangulation of GRB030509 (small errror box)
  3. IPN triangulation of GRB030509 - correction
  4. IPN triangulation of GRB030509 (single error box)
  5. GRB030329: RTT150 optical observations
  6. GRB030329, BVRI photometry
  7. GRB030429, refiend optical brightness
  8. GRB 030329: Optical limit (contemporaneous photography)
  9. GRB030418, BVRcIc field photometry
  10. GRB 030429: Redshift of neighbor galaxy
  11. GRB030429, BVRcIc field photometry
  12. GRB030429: RTT150 optical obs., correction to GCN 2208
  13. GRB 030329: High-Resolution Spectroscopy of the Host
  14. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  15. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  16. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  17. GRB030429: RTT150 optical observations, a possible host galaxy
  18. IPN triangulation of GRB030506 (annulus)
  19. IPN triangulation of GRB030505B (large error box)
  20. IPN triangulation of GRB030505A (annulus)
  21. GRB030329: RTT150 optical observations and upper limit for a host
  22. GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
  23. GRB030501, optical observation
  24. GRB030501 observation report
  25. GRB030501C triangulation (annulus)
  26. GRB030501 triangulation (correction to GCN 2194)
  27. GRB030329: RTT150 optical observations and upper limit for a host
  28. GRB 030429: Radio Observations
  29. GRB 030429: redshift from VLT spectroscopy
  30. GRB 030429: IR photometry with IRSF/SIRIUS
  31. GRB030501B triangulation (single error box)
  32. GRB 030329 Optical Observations
  33. GRB030328, optical observation
  34. GRB 030329, BVRI photometry
  35. GRB030429: Optical Observations
  36. GRB030501: TAROT candidate afterglow present in archival images
  37. GRB 030501: TAROT possible candidate counterpart
  38. IPN triangulation of GRB030501 (IBIS event; annulus)
  39. IPN triangulation of GRB030501B (annulus)
  40. GRB 030429: confirmation of afterglow candidate
  41. GRB030429, possible optical counterpart
  42. GRB030501 localized by INTEGRAL
  43. GRB030425: CrAO optical observation
  44. IPN triangulation of GRB030429 (annulus)
  45. IPN triangulation of GRB030428 (two large error boxes)
  46. GRB 030329 Oprical observations in Rozhen observatory
  47. GRB 030429: ROTSE-III observations
  48. GRB 030324: Radio Observations
  49. GRB030329 observed as a sudden ionospheric disturbance (SID)
  50. IPN triangulation of GRB030426 (annulus)
  51. SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
  52. IPN triangulation of GRB030425 (single error box)
  53. GRB030329, SPM optical observations (Correction)
  54. GRB030329, SPM optical observations
  55. GRB 030329, the review of the sky area in plate archive (1950-1998)
  56. GRB 030329: Spectral Evolution of SN 2003dh
  57. Optical Observations of GRB 030418 with Magellan
  58. GRB 030329: optical spectropolarimetry at VLT
  59. IPN triangulation of GRB030422C (annulus)
  60. IPN triangulation of GRB030422B (annulus)
  61. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  62. GRB030329: optical polarization
  63. IPN triangulation of GRB030422 (two large error boxes)
  64. GRB 030329 3.5 and 6 cm radio observations at RTF-32 telescope
  65. GRB030329, optical observation
  66. IPN triangulation of GRB030421 (annulus)
  67. MASTER:optical observations GRB030418
  68. MASTER:optical observations probable GRB030414
  69. GRB030329: 444 AAVSO Measurements
  70. IPN triangulation of GRB030419 (annulus)
  71. MASTER:optical observations GRB030416
  72. ROTSE-III prompt optical detections of GRB 030418
  73. GRB030418: Upper limits from recent and historical observations.
  74. GRB030418: Kiso near infrared observations
  75. GRB 030418: Optical afterglow
  76. GRB 030418: Finder for afterglow candidate
  77. GRB 030418: Optical afterglow candidate
  78. GRB 030329 OT position
  79. GRB030329: Optical Observations
  80. OT GRB 030329: early UBVRcIc spectral evolution
  81. GRB030329, UBVRI polarimetry, R-polarization
  82. GRB 030329: SARA Optical Observations
  83. OT GRB 030329: early spectrum
  84. GRB030329: VR Photometry at TNG
  85. GRB030324: Candidate Optical Afterglow (Erratum)
  86. GRB030324: Candidate Optical Afterglow
  87. IPN triangulation of GRB030414 (small error box)
  88. GRB 030413: Optical Observations
  89. GRB 030329 Rc observations
  90. IPN triangulation of GRB030413 (small error box)
  91. IPN triangulation of GRB030410 (annulus)
  92. Superluminal motion in GRB 030329 (Correction)
  93. Superluminal motion in GRB 030329
  94. GRB 030329 and SN 2003dh
  95. GRB030329, optical position
  96. GRB 030329 VLBA Observations
  97. CORRECTION TO IPN TRIANGULATION OF GRB050403
  98. IPN triangulation of GRB030406 (small error box)
  99. IPN triangulation of GRB050403 (small error box)
  100. IPN triangulation of GRB030403 (annulus)

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