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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"

32506 results found.

  1. XRF030824: Palomar observations
  2. GRB030823: optical observation at Tokyo Tech
  3. RAPTOR observations of GRB030823
  4. IPN triangulation of GRB030821 (=H2814; refined error box)
  5. GRB 030821(=H2814): A Faint, Long GRB Localized by the HETE WXM and the IPN
  6. Summary of recent IPN and HETE detections of SGR bursts
  7. Clarification of GCN 2354 on SGR1806-20
  8. IPN detection of continued activity from SGR1806-20
  9. 030813 SGR event (Konus-Wind observation)
  10. SGR 1808-20 (=H2802): A Possible new SGR
  11. GRB 021206 Optical Observations
  12. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  13. IPN/HETE summary of recent bursts from SGR1806-20
  14. XRF 030723: Detection of a rebrightening in the optical afterglow
  15. GRB030725: Optical observations
  16. XRF030723, BVRcIc field photometry update
  17. GRB021206 optical counterpart upper limit
  18. XRF030723: Re-analysis of ROTSE-III early images
  19. IPN triangulation of GRB030725 (=H2779; small error box)
  20. XRF030723 (=H2777): Second Epoch Magellan Observations
  21. GRB 030725: optical observations.
  22. GRB030725, optical transient observations
  23. XRF030723 Radio Observations
  24. XRF 030723: confirmation of fading optical counterpart
  25. XRF030723(=H2777): Chandra Observations
  26. XRF 030723: VLT spectra
  27. Magellan Observations of XRF030723 (=H2777)
  28. GRB030723: Upper limits from historical observations
  29. GRB030725, possible optical transient
  30. XRF030723: Palomar observations and proposed counterpart
  31. GRB030725 (=H2779): A Bright GRB Localized by HETE
  32. XRF030723: optical observations
  33. XRF030723 (= H2777): Chandra Observations Scheduled
  34. XRF030723, BVRcIc field photometry
  35. XRF030723, optical observations
  36. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  37. Konus-Wind detection of the bursts from SGR1806-20 region
  38. SGR 1806-20, submm observations
  39. RXTE PCA Observations of SGR1806-20 Region
  40. GRB030329: Subaru Optical Spectroscopy
  41. Triangulation of GRB030715 (single large error box)
  42. Triangulation of GRB030714 (single large error box)
  43. GRB030329: RTT150 optical observations
  44. GRBlog: Compilation of all GCN Circ. data
  45. GRB030706 triangulation (single large error box)
  46. GRB030329, optical observation in May
  47. IPN triangulation of GRB030626 (single large error box)
  48. GRB030418: R optical observations
  49. Final IPN error ellipse for GRB021206 (the polarized GRB)
  50. GRB 021206, Radio afterglow candidate
  51. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  52. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  53. GRB 030528: Optical Observations
  54. GRB 030528: tentative NIR counterpart
  55. GRB 030528, radio observations
  56. GRB030329, further radio observations at GMRT
  57. GRB030528, BVRI field photometry
  58. GRB030329, SPM optical observations
  59. GRB030528: Chandra TOO Planned
  60. GRB 030519B: optical observations.
  61. GRB 030329: optical observations
  62. GRB 030329/SN 2003dh: Jitter Episode
  63. GRB 030528, Teramo optical observation
  64. GRB 030528 Bisei optical observation
  65. GRB030528 (H2724): A long GRB localized by HETE
  66. GRB 030329: Correction to GCN 2254
  67. GRB 030329: Optical Observations
  68. GRB 030416: Optical Observations
  69. GRB030329, Optical observations
  70. GRB 030329/SN 2003dh: Possible increase in brightness
  71. GRB 030329: HST ACS Observations of the Host
  72. GRB 030329 Optical Observations
  73. GRB030329: XMM-Newton observation
  74. GRB030324: Further Observations of the Candidate Optical Afterglow
  75. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  76. IPN triangulation of GRB030519B=H2716 (small error box)
  77. GRB 030418: Second Epoch Optical Observations with Magellan
  78. GRB030519B (=H2716): A Long, Bright GRB Localized by the HETE WXM
  79. HETE GRB030329, correction to Rc Observations in Loiano
  80. GRB 030329: Optical limit (contemporaneous imaging)
  81. GRB 030501: final TAROT limits
  82. IPN triangulation of GRB030509 (small errror box)
  83. IPN triangulation of GRB030509 - correction
  84. GRB030329: RTT150 optical observations
  85. GRB030329, BVRI photometry
  86. GRB030429, refiend optical brightness
  87. GRB 030329: Optical limit (contemporaneous photography)
  88. GRB030418, BVRcIc field photometry
  89. GRB 030429: Redshift of neighbor galaxy
  90. GRB030429, BVRcIc field photometry
  91. GRB030429: RTT150 optical obs., correction to GCN 2208
  92. GRB 030329: High-Resolution Spectroscopy of the Host
  93. GRB030429 (=H2695): A Long GRB Localized by the HETE WXM and SXC
  94. GRB030418 (=H2686): A Long, X-Ray-Rich GRB Localized by the HETE WXM
  95. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  96. GRB030429: RTT150 optical observations, a possible host galaxy
  97. GRB030329: RTT150 optical observations and upper limit for a host
  98. GRB030501, optical observation
  99. GRB030501 observation report
  100. GRB030501 triangulation (correction to GCN 2194)

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