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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

22054 results found.

  1. GRB030913, candidate afterglow observations
  2. GRB 030913, optical candidate
  3. GRB030913: AAVSO optical observations
  4. GRB 030913, BOOTES observations
  5. GRB030913 (=H2849): Confirmation of the Flight Localization
  6. GRB030913 (=H2849): TAROT Observations
  7. Magellan Observations of GRB030725 (=H2779)
  8. XRF 020427: Gemini-South Spectroscopic Observations of the Host
  9. XRF030824: Optical observations
  10. IBAS detection of bursts from SGR 1806-20
  11. Radio Observations of SGR1806-20
  12. INTEGRAL ToO OBSERVATIONS OF SGR1806-20: CALL FOR CORRELATED OBSERVATIONS
  13. XRF030824: Second-epoch Palomar observations
  14. XRF030824: optical observations
  15. GRB030823: optical observations
  16. GRB030823: Palomar observations
  17. XRF030824: Palomar observations
  18. GRB 030824: Candidate Afterglow (or Variable/Flare Star?)
  19. RAPTOR observations of GRB030823
  20. Lulin follow-up observations of GRB030823
  21. Summary of recent IPN and HETE detections of SGR bursts
  22. GRB 030817 = H2808 TAROT optical observations
  23. SGR 1808-20 (=H2802): A Possible new SGR
  24. GRB 021206 Optical Observations
  25. XRF 030723: Detection of a rebrightening in the optical afterglow
  26. GRB030725: Optical observations
  27. GRB021206 optical counterpart upper limit
  28. XRF030723: Re-analysis of ROTSE-III early images
  29. XRF030723 (=H2777): Second Epoch Magellan Observations
  30. GRB 030725: optical observations.
  31. GRB030725, optical transient observations
  32. XRF030723 Radio Observations
  33. XRF 030723: confirmation of fading optical counterpart
  34. XRF030723(=H2777): Chandra Observations
  35. XRF 030723: VLT spectra
  36. Magellan Observations of XRF030723 (=H2777)
  37. GRB030723: Upper limits from historical observations
  38. GRB030725, possible optical transient
  39. XRF030723: Palomar observations and proposed counterpart
  40. XRF030723: optical observations
  41. XRF030723 (= H2777): Chandra Observations Scheduled
  42. XRF030723, ROTSE-III Early Observations
  43. XRF030723, BVRcIc field photometry
  44. XRF 030723, optical observations
  45. XRF030723, optical observations
  46. XRF 030723, optical observations
  47. GRB030723, optical observations
  48. Konus-Wind detection of the bursts from SGR1806-20 region
  49. SGR 1806-20, submm observations
  50. RXTE PCA Observations of SGR1806-20 Region
  51. GRB030329: RTT150 optical observations
  52. IPN triangulation of GRB030711 (annulus, =SGR0525-66?)
  53. GRB030329, optical observation in May
  54. GRB030418: R optical observations
  55. GRB 021206, Radio afterglow candidate
  56. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  57. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  58. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  59. GRB 030528: Optical Observations
  60. GRB 030528: tentative NIR counterpart
  61. GRB 030528, radio observations
  62. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  63. GRB030329, further radio observations at GMRT
  64. GRB030329, SPM optical observations
  65. GRB030528: Chandra TOO Planned
  66. GRB 030519B: optical observations.
  67. MASTER: optical observation GRB030601
  68. GRB030528(=H2724): Revised SXC Localization
  69. GRB 030329: optical observations
  70. GRB 030329/SN 2003dh: Jitter Episode
  71. GRB 030329: Correction to GCN 2254
  72. GRB 030329: Optical Observations
  73. GRB 030528: Optical observations at RIKEN
  74. GRB 030416: Optical Observations
  75. GRB 030329: optical photometry at various french observatories
  76. GRB030329, Optical observations
  77. GRB 030329/SN 2003dh: Possible increase in brightness
  78. GRB 030329: HST ACS Observations of the Host
  79. GRB 030329 Optical Observations
  80. GRB030329: XMM-Newton observation
  81. GRB 021004: HST observations
  82. GRB030324: Further Observations of the Candidate Optical Afterglow
  83. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  84. GRB 030418: Second Epoch Optical Observations with Magellan
  85. HETE GRB030329, correction to Rc Observations in Loiano
  86. GRB 030329: Optical limit (contemporaneous imaging)
  87. GRB 030501: final TAROT limits
  88. GRB030329: RTT150 optical observations
  89. GRB030329, BVRI photometry
  90. GRB030429: RTT150 optical observations, a possible host galaxy
  91. GRB030329: RTT150 optical observations and upper limit for a host
  92. GRB030501, optical observation
  93. GRB030329: RTT150 optical observations and upper limit for a host
  94. GRB 030429: Radio Observations
  95. GRB 030429: IR photometry with IRSF/SIRIUS
  96. GRB 030329 Optical Observations
  97. GRB030429: Optical Observations
  98. GRB030501: TAROT candidate afterglow present in archival images
  99. GRB 030501: TAROT possible candidate counterpart
  100. GRB 030429: confirmation of afterglow candidate

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