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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"

32494 results found.

  1. IPN/HETE summary of recent bursts from SGR1806-20
  2. XRF 030723: Detection of a rebrightening in the optical afterglow
  3. GRB030725: Optical observations
  4. XRF030723, BVRcIc field photometry update
  5. GRB021206 optical counterpart upper limit
  6. XRF030723: Re-analysis of ROTSE-III early images
  7. IPN triangulation of GRB030725 (=H2779; small error box)
  8. XRF030723 (=H2777): Second Epoch Magellan Observations
  9. GRB 030725: optical observations.
  10. GRB030725, optical transient observations
  11. XRF030723 Radio Observations
  12. XRF 030723: confirmation of fading optical counterpart
  13. XRF030723(=H2777): Chandra Observations
  14. XRF 030723: VLT spectra
  15. Magellan Observations of XRF030723 (=H2777)
  16. GRB030723: Upper limits from historical observations
  17. GRB030725, possible optical transient
  18. XRF030723: Palomar observations and proposed counterpart
  19. GRB030725 (=H2779): A Bright GRB Localized by HETE
  20. XRF030723: optical observations
  21. XRF030723 (= H2777): Chandra Observations Scheduled
  22. XRF030723, BVRcIc field photometry
  23. XRF030723, optical observations
  24. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  25. Konus-Wind detection of the bursts from SGR1806-20 region
  26. SGR 1806-20, submm observations
  27. RXTE PCA Observations of SGR1806-20 Region
  28. GRB030329: Subaru Optical Spectroscopy
  29. Triangulation of GRB030715 (single large error box)
  30. Triangulation of GRB030714 (single large error box)
  31. GRB030329: RTT150 optical observations
  32. GRBlog: Compilation of all GCN Circ. data
  33. GRB030706 triangulation (single large error box)
  34. GRB030329, optical observation in May
  35. IPN triangulation of GRB030626 (single large error box)
  36. GRB030418: R optical observations
  37. Final IPN error ellipse for GRB021206 (the polarized GRB)
  38. GRB 021206, Radio afterglow candidate
  39. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  40. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  41. GRB 030528: Optical Observations
  42. GRB 030528: tentative NIR counterpart
  43. GRB 030528, radio observations
  44. GRB030329, further radio observations at GMRT
  45. GRB030528, BVRI field photometry
  46. GRB030329, SPM optical observations
  47. GRB030528: Chandra TOO Planned
  48. GRB 030519B: optical observations.
  49. GRB 030329: optical observations
  50. GRB 030329/SN 2003dh: Jitter Episode
  51. GRB 030528, Teramo optical observation
  52. GRB 030528 Bisei optical observation
  53. GRB030528 (H2724): A long GRB localized by HETE
  54. GRB 030329: Correction to GCN 2254
  55. GRB 030329: Optical Observations
  56. GRB 030416: Optical Observations
  57. GRB030329, Optical observations
  58. GRB 030329/SN 2003dh: Possible increase in brightness
  59. GRB 030329: HST ACS Observations of the Host
  60. GRB 030329 Optical Observations
  61. GRB030329: XMM-Newton observation
  62. GRB030324: Further Observations of the Candidate Optical Afterglow
  63. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  64. IPN triangulation of GRB030519B=H2716 (small error box)
  65. GRB 030418: Second Epoch Optical Observations with Magellan
  66. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  67. HETE GRB030329, correction to Rc Observations in Loiano
  68. GRB 030329: Optical limit (contemporaneous imaging)
  69. GRB 030501: final TAROT limits
  70. IPN triangulation of GRB030509 (small errror box)
  71. IPN triangulation of GRB030509 - correction
  72. GRB030329: RTT150 optical observations
  73. GRB030329, BVRI photometry
  74. GRB030429, refiend optical brightness
  75. GRB 030329: Optical limit (contemporaneous photography)
  76. GRB030418, BVRcIc field photometry
  77. GRB 030429: Redshift of neighbor galaxy
  78. GRB030429, BVRcIc field photometry
  79. GRB030429: RTT150 optical obs., correction to GCN 2208
  80. GRB 030329: High-Resolution Spectroscopy of the Host
  81. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  82. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  83. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  84. GRB030429: RTT150 optical observations, a possible host galaxy
  85. GRB030329: RTT150 optical observations and upper limit for a host
  86. GRB030501, optical observation
  87. GRB030501 observation report
  88. GRB030501 triangulation (correction to GCN 2194)
  89. GRB030329: RTT150 optical observations and upper limit for a host
  90. GRB 030429: Radio Observations
  91. GRB 030429: redshift from VLT spectroscopy
  92. GRB 030429: IR photometry with IRSF/SIRIUS
  93. GRB030501B triangulation (single error box)
  94. GRB 030329 Optical Observations
  95. GRB030328, optical observation
  96. GRB 030329, BVRI photometry
  97. GRB030429: Optical Observations
  98. GRB030501: TAROT candidate afterglow present in archival images
  99. GRB 030501: TAROT possible candidate counterpart
  100. IPN triangulation of GRB030501 (IBIS event; annulus)

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