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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"

32511 results found.

  1. IBAS detection of bursts from SGR 1806-20
  2. Radio Observations of SGR1806-20
  3. GRB 030824: Candidate Follow-Up
  4. XRF030824: Second-epoch Palomar observations
  5. XRF030824: optical observations
  6. XRF030824: Palomar observations
  7. GRB030823: optical observation at Tokyo Tech
  8. RAPTOR observations of GRB030823
  9. IPN triangulation of GRB030821 (=H2814; refined error box)
  10. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  11. Summary of recent IPN and HETE detections of SGR bursts
  12. Clarification of GCN 2354 on SGR1806-20
  13. IPN detection of continued activity from SGR1806-20
  14. 030813 SGR event (Konus-Wind observation)
  15. SGR 1808-20 (=H2802): A Possible new SGR
  16. GRB 021206 Optical Observations
  17. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  18. IPN/HETE summary of recent bursts from SGR1806-20
  19. XRF 030723: Detection of a rebrightening in the optical afterglow
  20. GRB030725: Optical observations
  21. XRF030723, BVRcIc field photometry update
  22. GRB021206 optical counterpart upper limit
  23. XRF030723: Re-analysis of ROTSE-III early images
  24. IPN triangulation of GRB030725 (=H2779; small error box)
  25. XRF030723 (=H2777): Second Epoch Magellan Observations
  26. GRB 030725: optical observations.
  27. GRB030725, optical transient observations
  28. XRF030723 Radio Observations
  29. XRF 030723: confirmation of fading optical counterpart
  30. XRF030723(=H2777): Chandra Observations
  31. XRF 030723: VLT spectra
  32. Magellan Observations of XRF030723 (=H2777)
  33. GRB030723: Upper limits from historical observations
  34. GRB030725, possible optical transient
  35. XRF030723: Palomar observations and proposed counterpart
  36. GRB030725 (=H2779): A Bright GRB Localized by HETE
  37. XRF030723: optical observations
  38. XRF030723 (= H2777): Chandra Observations Scheduled
  39. XRF030723, BVRcIc field photometry
  40. XRF030723, optical observations
  41. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  42. Konus-Wind detection of the bursts from SGR1806-20 region
  43. SGR 1806-20, submm observations
  44. RXTE PCA Observations of SGR1806-20 Region
  45. GRB030329: Subaru Optical Spectroscopy
  46. Triangulation of GRB030715 (single large error box)
  47. Triangulation of GRB030714 (single large error box)
  48. GRB030329: RTT150 optical observations
  49. GRBlog: Compilation of all GCN Circ. data
  50. GRB030706 triangulation (single large error box)
  51. GRB030329, optical observation in May
  52. IPN triangulation of GRB030626 (single large error box)
  53. GRB030418: R optical observations
  54. Final IPN error ellipse for GRB021206 (the polarized GRB)
  55. GRB 021206, Radio afterglow candidate
  56. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  57. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  58. GRB 030528: Optical Observations
  59. GRB 030528: tentative NIR counterpart
  60. GRB 030528, radio observations
  61. GRB030329, further radio observations at GMRT
  62. GRB030528, BVRI field photometry
  63. GRB030329, SPM optical observations
  64. GRB030528: Chandra TOO Planned
  65. GRB 030519B: optical observations.
  66. GRB 030329: optical observations
  67. GRB 030329/SN 2003dh: Jitter Episode
  68. GRB 030528, Teramo optical observation
  69. GRB 030528 Bisei optical observation
  70. GRB030528 (H2724): A long GRB localized by HETE
  71. GRB 030329: Correction to GCN 2254
  72. GRB 030329: Optical Observations
  73. GRB 030416: Optical Observations
  74. GRB030329, Optical observations
  75. GRB 030329/SN 2003dh: Possible increase in brightness
  76. GRB 030329: HST ACS Observations of the Host
  77. GRB 030329 Optical Observations
  78. GRB030329: XMM-Newton observation
  79. GRB030324: Further Observations of the Candidate Optical Afterglow
  80. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  81. IPN triangulation of GRB030519B=H2716 (small error box)
  82. GRB 030418: Second Epoch Optical Observations with Magellan
  83. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  84. HETE GRB030329, correction to Rc Observations in Loiano
  85. GRB 030329: Optical limit (contemporaneous imaging)
  86. GRB 030501: final TAROT limits
  87. IPN triangulation of GRB030509 (small errror box)
  88. IPN triangulation of GRB030509 - correction
  89. GRB030329: RTT150 optical observations
  90. GRB030329, BVRI photometry
  91. GRB030429, refiend optical brightness
  92. GRB 030329: Optical limit (contemporaneous photography)
  93. GRB030418, BVRcIc field photometry
  94. GRB 030429: Redshift of neighbor galaxy
  95. GRB030429, BVRcIc field photometry
  96. GRB030429: RTT150 optical obs., correction to GCN 2208
  97. GRB 030329: High-Resolution Spectroscopy of the Host
  98. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  99. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  100. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM

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