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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').
  1. GRB 030528 Bisei optical observation
  2. GRB030528 (H2724): A long GRB localized by HETE
  3. GRB 030329: Correction to GCN 2254
  4. GRB 030329: Optical Observations
  5. GRB 030528: Optical observations at RIKEN
  6. GRB 030528 (=H2724) Kyoto optical observation
  7. IPN triangulation of GRB030523B (annulus)
  8. GRB 030416: Optical Observations
  9. GRB 030329: Planned XMM-Newton Observation
  10. IPN triangulation of GRB030523 (annulus)
  11. GRB 030329: optical photometry at various french observatories
  12. GRB 030329: optical photometry at Belesta observatory (France)
  13. GRB030329, Optical observations
  14. GRB 030329/SN 2003dh: Possible increase in brightness
  15. GRB 030329: HST ACS Observations of the Host
  16. GRB 030329 Optical Observations
  17. GRB030329: XMM-Newton observation
  18. GRB 021004: HST observations
  19. GRB030324: Further Observations of the Candidate Optical Afterglow
  20. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  21. IPN triangulation of GRB030519B=H2716 (small error box)
  22. GRB 030418: Second Epoch Optical Observations with Magellan
  23. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  24. IPN triangulation of GRB030519 (annulus)
  25. IPN triangulation of GRB030518C (annulus)
  26. IPN triangulation of GRB030518B (annulus)
  27. IPN triangulation of GRB030518A (annulus)
  28. IPN triangulation of GRB030514 (annulus)
  29. HETE GRB030329, correction to Rc Observations in Loiano
  30. IPN triangulation of GRB030513 (annulus)
  31. IPN triangulation of GRB030509B (annulus)
  32. GRB 030329: Optical limit (contemporaneous imaging)
  33. GRB 030501: final TAROT limits
  34. IPN triangulation of GRB030509 (small errror box)
  35. IPN triangulation of GRB030509 - correction
  36. IPN triangulation of GRB030509 (single error box)
  37. GRB030329: RTT150 optical observations
  38. GRB030329, BVRI photometry
  39. GRB030429, refiend optical brightness
  40. GRB 030329: Optical limit (contemporaneous photography)
  41. GRB030418, BVRcIc field photometry
  42. GRB 030429: Redshift of neighbor galaxy
  43. GRB030429, BVRcIc field photometry
  44. GRB030429: RTT150 optical obs., correction to GCN 2208
  45. GRB 030329: High-Resolution Spectroscopy of the Host
  46. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  47. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  48. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  49. GRB030429: RTT150 optical observations, a possible host galaxy
  50. IPN triangulation of GRB030506 (annulus)
  51. IPN triangulation of GRB030505B (large error box)
  52. IPN triangulation of GRB030505A (annulus)
  53. GRB030329: RTT150 optical observations and upper limit for a host
  54. GRB 030329: all-sky CCD images by K. Shiokawa immediately after the burst
  55. GRB030501, optical observation
  56. GRB030501 observation report
  57. GRB030501C triangulation (annulus)
  58. GRB030501 triangulation (correction to GCN 2194)
  59. GRB030329: RTT150 optical observations and upper limit for a host
  60. GRB 030429: Radio Observations
  61. GRB 030429: redshift from VLT spectroscopy
  62. GRB 030429: IR photometry with IRSF/SIRIUS
  63. GRB030501B triangulation (single error box)
  64. GRB 030329 Optical Observations
  65. GRB030328, optical observation
  66. GRB 030329, BVRI photometry
  67. GRB030429: Optical Observations
  68. GRB030501: TAROT candidate afterglow present in archival images
  69. GRB 030501: TAROT possible candidate counterpart
  70. IPN triangulation of GRB030501 (IBIS event; annulus)
  71. IPN triangulation of GRB030501B (annulus)
  72. GRB 030429: confirmation of afterglow candidate
  73. GRB030429, possible optical counterpart
  74. GRB030501 localized by INTEGRAL
  75. GRB030425: CrAO optical observation
  76. IPN triangulation of GRB030429 (annulus)
  77. IPN triangulation of GRB030428 (two large error boxes)
  78. GRB 030329 Oprical observations in Rozhen observatory
  79. GRB 030429: ROTSE-III observations
  80. GRB 030324: Radio Observations
  81. GRB030329 observed as a sudden ionospheric disturbance (SID)
  82. IPN triangulation of GRB030426 (annulus)
  83. SNeIa AS THE POSSIBLE PROGENITORS OF SHORT-DURATION GRBs.
  84. IPN triangulation of GRB030425 (single error box)
  85. GRB030329, SPM optical observations (Correction)
  86. GRB030329, SPM optical observations
  87. GRB 030329, the review of the sky area in plate archive (1950-1998)
  88. GRB 030329: Spectral Evolution of SN 2003dh
  89. Optical Observations of GRB 030418 with Magellan
  90. GRB 030329: optical spectropolarimetry at VLT
  91. IPN triangulation of GRB030422C (annulus)
  92. IPN triangulation of GRB030422B (annulus)
  93. GRB 030329: wide-field photograph by R. Tamura 1 hr after the burst
  94. GRB030329: optical polarization
  95. IPN triangulation of GRB030422 (two large error boxes)
  96. GRB 030329 3.5 and 6 cm radio observations at RTF-32 telescope
  97. GRB030329, optical observation
  98. IPN triangulation of GRB030421 (annulus)
  99. MASTER:optical observations GRB030418
  100. MASTER:optical observations probable GRB030414

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