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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"

32509 results found.

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

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