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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

32720 results found.

  1. EP241103a: EP observation update
  2. LIGO/Virgo/KAGRA S241102br: EP-WXT X-ray follow-up and flux limits
  3. GRB 241030A: Swift-UVOT observations of the optical prompt flare
  4. EP241103a: GSP optical upper limit
  5. EP241103A: LCO optical observations
  6. EP241103a: Global MASTER-Net observations report
  7. GRB 241030A: Rapid release of TESS data.
  8. EP241101a: Global MASTER-Net observations report
  9. GRB 241029A: GRBAlpha detection
  10. LIGO/Virgo/KAGRA S241101ee: Updated Sky localization
  11. S241102cy: Identification of a GW compact binary merger candidate
  12. LIGO/Virgo/KAGRA S241102br: Identification of a GW compact binary merger candidate
  13. Kinder optical follow-up observations of EP241021a, EP241026b, and EP241030a/GRB241030A
  14. GRB241030A: OHP/T193 optical observations
  15. EP241030a: Futher EP-FXT observation of the X-ray Afterglow of GRB 241030A
  16. Swift GRB 241101A: Global MASTER-Net observations report
  17. LIGO/Virgo/KAGRA S241101ee: Identification of a GW compact binary merger candidate
  18. GRB 241030A/EP241030a: TNOT observations of the optical counterpart
  19. EP241021a: Upper limit from Konus-Wind observations
  20. GRB 241101A: Swift-BAT refined analysis
  21. GRB 241030A: further SAO RAS optical observations
  22. GRB 241030A: Optical Observations via Virtual Telescope Project
  23. EP241021a: Liverpool Telescope optical follow-up observations
  24. GRB 241026A: SAO RAS optical observations
  25. GRB 241030A / EP241030a: GMG possible spectroscopic redshift at z ~ 1.4
  26. EP241030a: EP/FXT observation of GRB 241030A X-ray Afterglow
  27. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits (duplicate submission of 38023)
  28. GRB 241030B: NUTTelA-TAO / BSTI Optical Limits
  29. EP241021a: OHP/T193 optical observations
  30. GRB 241030A: Palomar 1-m telescope COSMOS optical observations
  31. GRB 241030B: Montarrenti Observatory optical upper limit
  32. GRB 241030A / EP241030a: FTW Optical and NIR observations of the optical counterpart
  33. EP241026b: Liverpool Telescope optical follow-up
  34. GRB 241030A: SAO RAS optical observations
  35. GRB 241030A: Fermi GBM Observation
  36. EP241021a: AMI-LA radio detection
  37. GRB 241030B : GIT optical upper limits
  38. GRB 241030B: LCOGT Optical Upper Limits
  39. GRB 241030B: Swift-BAT refined analysis
  40. GRB 241030A: Swift-BAT refined analysis
  41. GRB 241029A: COLIBRI Detection of the Optical Counterpart
  42. GRB 241030B: Swift/UVOT Detection
  43. EP EP241030a: Global MASTER-Net observations report
  44. GRB 241029A: LCO optical detection
  45. GRB 241030B: GTC/OSIRIS+ tentative spectroscopic redshift z = 2.82
  46. GRB 241030B: SVOM/GRM observation
  47. GRB 241030B : MITSuME Akeno optical upper limits
  48. GRB 241030A: COLIBRI Continuing Detection of the Afterglow
  49. GRB 241030B: SVOM/VT optical afterglow observations
  50. GRB 241030B: COLIBRÍ Upper Limits on the Optical Counterpart
  51. EP241030a: EP detection of GRB 241030A X-ray Afterglow
  52. GRB241030B: Fermi GBM Observation
  53. GRB 241030B: BTA observations
  54. GRB 241029A: SVOM/VT optical afterglow observations
  55. GRB 241030A: detection of the bright optical counterpart in ATLAS forced photometry
  56. GRB 241030B: optical observations from the INAF Asiago Observatory
  57. EP241021a: Swift-UVOT detection
  58. GRB241030B: GRANDMA/TAROT Upper Limit
  59. GRB 241030B: SAO RAS optical observations
  60. GRB 241030B: AKO Optical Afterglow Detection
  61. GRB 241030B: Nanshan/HMT optical afterglow detection
  62. GRB 241030B: SVOM/ECLAIRs detection of a burst
  63. Konus-Wind detection of GRB 241030A
  64. GRB 241030A: Fermi-LAT detection
  65. GRB 240912A: radio detection with the VLA
  66. Fermi GRB 241030A: Global MASTER-Net observations report
  67. GRB 241030A: AKO Optical Afterglow Detection
  68. Swift GRB 241030A: Global MASTER-Net observations report
  69. GRB 241030A: Swift/UVOT Detection
  70. EP 241021a: further Swift-XRT observations and X-ray counterpart detection
  71. GRB 241030A: SVOM/GRM observation
  72. GRB 241026A: Swift-BAT refined analysis
  73. GRB 241030A: SVOM/C-GFT optical observations
  74. GRB 241026A: LBT optical observations
  75. EP241021a: Optical rebrightening observations with Mephisto
  76. EP241026b: EP-FXT follow-up observation
  77. GRB 241030A: Multiband optical detection with Mephisto
  78. GRB 241030A: SVOM/VT optical afterglow observations
  79. GRB 241025A: The discovery of a BdHN I from data of Swift, Fermi, SVOM and Einstein Probe telescopes
  80. GRB 241030A : MITSuME Akeno optical afterglow detection
  81. GRB 241029A: GROWTH-India Telescope optical follow up
  82. GRB 241030A: TRT optical observations
  83. GRB 241030A: Keck/LRIS spectroscopic redshift z = 1.411
  84. GRB 241030A: ULL-ASTRO-MASTER detection of a bright optical counterpart with the LCOGT 40-cm telescope at McDonald Observatory
  85. GRB 241030A: COLIBRÍ Detection of the Bright Optical Counterpart
  86. GRB 241029A: SAO RAS optical observations
  87. GRB 241026A: SAO RAS optical observations
  88. EP240919a / GRB 240919A: ATCA Detection of Radio Counterpart
  89. EP241021a: SAO RAS observations of rebrightening
  90. GRB 241029A: GTC/OSIRIS+ spectroscopic redshift z=1.072
  91. EP241021a: ATCA radio observations
  92. MISTRAL@OHP photometric and spectroscopic observations of GRB 241029A
  93. GRB 241026A: Swift/UVOT Upper Limits
  94. GRB 241029A: Swift-XRT observations
  95. GRB 241029A: Fermi GBM Observation
  96. GRB 241029A: AKO Optical Afterglow Detection
  97. GRB 241029A: GOTO optical afterglow detection
  98. EP241021a: continued SOAR observations confirm optical rebrightening
  99. GRB 241029A: MASTER early optical counterpart detection
  100. GRB 241029A: Xinglong-2.16m optical afterglow confirmation

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