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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"

21790 results found.

  1. XRF030824: optical observations
  2. GRB030823: optical observations
  3. GRB030823: Palomar observations
  4. XRF030824: Palomar observations
  5. RAPTOR observations of GRB030823
  6. Lulin follow-up observations of GRB030823
  7. GRB 030817 = H2808 TAROT optical observations
  8. SGR 1808-20 (=H2802): A Possible new SGR
  9. GRB 021206 Optical Observations
  10. XRF030723(=H2777): Chandra Fading X-ray Afterglow Confirmed
  11. XRF 030723: Detection of a rebrightening in the optical afterglow
  12. GRB030725: Optical observations
  13. GRB021206 optical counterpart upper limit
  14. XRF030723: Re-analysis of ROTSE-III early images
  15. XRF030723 (=H2777): Second Epoch Magellan Observations
  16. GRB 030725: optical observations.
  17. GRB030725, optical transient observations
  18. XRF030723 Radio Observations
  19. XRF 030723: confirmation of fading optical counterpart
  20. XRF030723(=H2777): Chandra Observations
  21. XRF 030723: VLT spectra
  22. Magellan Observations of XRF030723 (=H2777)
  23. GRB030723: Upper limits from historical observations
  24. GRB030725, possible optical transient
  25. XRF030723: Palomar observations and proposed counterpart
  26. XRF030723: optical observations
  27. XRF030723 (= H2777): Chandra Observations Scheduled
  28. XRF030723, ROTSE-III Early Observations
  29. XRF030723, BVRcIc field photometry
  30. XRF 030723, optical observations
  31. XRF030723, optical observations
  32. XRF 030723, optical observations
  33. GRB030723, optical observations
  34. Konus-Wind detection of the bursts from SGR1806-20 region
  35. SGR 1806-20, submm observations
  36. RXTE PCA Observations of SGR1806-20 Region
  37. GRB030329: RTT150 optical observations
  38. GRB030329, optical observation in May
  39. GRB030418: R optical observations
  40. GRB 021206, Radio afterglow candidate
  41. GRB030528(=H2724): X-ray Afterglow Identified in Second Epoch
  42. GRB030329, SPM optical observations (Correction of GCN2075 R band)
  43. GRB 030528: Infrared Observations and the Proposed IR Counterpart
  44. GRB 030528: Optical Observations
  45. GRB 030528, radio observations
  46. GRB030528(=H2724): Observations with the Chandra X-ray Observatory
  47. GRB030329, further radio observations at GMRT
  48. GRB030329, SPM optical observations
  49. GRB030528: Chandra TOO Planned
  50. GRB 030519B: optical observations.
  51. MASTER: optical observation GRB030601
  52. GRB 030329: optical observations
  53. GRB 030329/SN 2003dh: Jitter Episode
  54. GRB 030329: Optical Observations
  55. GRB 030528: Optical observations at RIKEN
  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. GRB 021004: HST observations
  63. GRB030324: Further Observations of the Candidate Optical Afterglow
  64. GRB030519B (=H2716): Peak Fluxes, Fluences, and Energy Spectrum
  65. GRB 030418: Second Epoch Optical Observations with Magellan
  66. HETE GRB030329, correction to Rc Observations in Loiano
  67. GRB030329: RTT150 optical observations
  68. GRB030329, BVRI photometry
  69. GRB 030429: Redshift of neighbor galaxy
  70. GRB 030329: High-Resolution Spectroscopy of the Host
  71. GRB030429: RTT150 optical observations, a possible host galaxy
  72. GRB030329: RTT150 optical observations and upper limit for a host
  73. GRB030501, optical observation
  74. GRB030329: RTT150 optical observations and upper limit for a host
  75. GRB 030429: Radio Observations
  76. GRB 030429: IR photometry with IRSF/SIRIUS
  77. GRB 030329 Optical Observations
  78. GRB030429: Optical Observations
  79. GRB 030501: TAROT possible candidate counterpart
  80. GRB 030429: confirmation of afterglow candidate
  81. GRB030429, possible optical counterpart
  82. GRB 030329 Oprical observations in Rozhen observatory
  83. GRB 030429: ROTSE-III observations
  84. GRB 030324: Radio Observations
  85. GRB030329 observed as a sudden ionospheric disturbance (SID)
  86. GRB030329, SPM optical observations (Correction)
  87. GRB030329, SPM optical observations
  88. GRB 030329, the review of the sky area in plate archive (1950-1998)
  89. Optical Observations of GRB 030418 with Magellan
  90. GRB 030329: optical spectropolarimetry at VLT
  91. GRB030329: optical polarization
  92. GRB 030329 3.5 and 6 cm radio observations at RTF-32 telescope
  93. MASTER:optical observations GRB030418
  94. MASTER:optical observations probable GRB030414
  95. GRB030329: 444 AAVSO Measurements
  96. MASTER:optical observations GRB030416
  97. ROTSE-III prompt optical detections of GRB 030418
  98. GRB030418: Upper limits from recent and historical observations.
  99. GRB030418: Kiso near infrared observations
  100. GRB 030418: Optical afterglow

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