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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.

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

16150 results found.

  1. GRB 230812B: continued SAO RAS optical observation
  2. GRB230815A: BOOTES-6/DPRT optical upper limit
  3. GRB 230812B: Tautenburg observations
  4. GRB 230812B: continued AbAO optical afterglow observations
  5. GRB 230812B: Optical observaions from Rozhen Observatory
  6. GRB 230812B: Further Bassano Bresciano Observatory optical observations
  7. GRB 230812B: further SAO RAS optical observations
  8. GRB 230812B: CrAO ZTSh optical observations
  9. GRB 230812B: Koshka Zeiss-1000 optical observations
  10. GRB 230812B: GIT optical follow-up
  11. GRB 230812B: Leavitt Observatory optical observations
  12. GRB 230812B : optical observations from Observatoire de Haute-Provence
  13. GRB 230812B: Bassano Bresciano Observatory optical observations
  14. GRB 230812B: Faulkes Telescope North optical afterglow follow-up
  15. GRB 230812B: Osservatorio Astronomico "Nastro Verde" optical observation
  16. GRB 230812B: OASDG optical observations
  17. GRB 230812B: AbAO optical observations
  18. GRB 230812B: Montarrenti Observatory optical observations
  19. GRB 230812B: SAO RAS optical observations
  20. GRB 230812B: Detected Optical Afterglow Candidate
  21. GRB 230812B: GMG - GRANDMA observations
  22. GRB 230812: Swift/UVOT Detection
  23. GOTO confirmation and possible host galaxy of GRB230812B optical afterglow
  24. GRB 230812B: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi GRB (Trigger 713559497)
  25. Fermi GRB 230812B: MASTER optical counterpart
  26. GRB 230812B: KAIT Optical Afterglow Candidate
  27. GRB 230805B: Iota Scorpii Observatory, La Spezia, Italy upper limit
  28. ZTF23aaoohpy/AT2023lcr: JWST observations consistent with the presence of a supernova
  29. GRB 230805B : MITSuME Akeno optical upper limits
  30. GRB 230805B : OHP/T193 optical upper limit
  31. GRB 230805B: Swift/UVOT Upper Limits
  32. GRB 230805B: Bassano Bresciano observatory upper limit
  33. GRB 230805B: BOOTES-6/DPRT optical upper limit and 1.5m OSN detection
  34. GRB 230805B: NOT optical afterglow confirmation
  35. GRB 230805B: SAO RAS optical observations
  36. GRB 230802A: Swift/UVOT Upper Limits
  37. GRB 230802A: BOOTES-5/JGT optical upper limit
  38. GRB 230723B: MITSuME Ishigaki optical observation
  39. GRB 230728A: BOOTES-1 optical upper limit
  40. GRB 230728A: LCOGT Optical Upper Limit
  41. GRB 230728A: Swift/UVOT Upper Limits
  42. GRB 230728A: NOT optical observations and possible host galaxy
  43. GRB 230723B: Further CAHA observations and host galaxy detection
  44. GRB 230723B: MITSuME Akeno optical afterglow candidate detection
  45. GRB 230723B: GAD Observatory, La Spezia, Italy upper limit
  46. GRB 230723B: Osservatorio Astronomico Nastro Verde upper limit
  47. GRB 230723B: Montarrenti Observatory upper limit
  48. GRB 230723B: Optical afterglow candidate from CAHA
  49. GRB 230723B: Bassano Bresciano Observatory upper limit
  50. GRB 230723B: Optical limit from CAHA
  51. GRB 230723B: Swift/UVOT Upper Limits
  52. LIGO/Virgo/KAGRA S230627c: GECKO optical follow-up observations of host galaxy candidates and ZTF23aaptsuy/AT2023lxu
  53. GRB 230328B: LBT detection of the likely host galaxy
  54. LIGO/Virgo/KAGRA S230627c: observations of ZTF23aaptsuy/AT2023lx in AbAO observatory
  55. GRB 230628E: Swift/UVOT Detection
  56. AT2023lcr (ATLAS23msn/ZTF23aaoohpy): ALMA 100 GHz Detection
  57. GRB 230628E - VLT spectroscopic observations
  58. ZTF23aaoohpy/AT2023lcr: LBT observations
  59. GRB230628E: VLT optical identification of afterglow candidate
  60. GRB 230628E: LCOGT Optical Upper Limit
  61. ZTF23aaoohpy /AT2023lcr: TNG NIR detection
  62. LIGO/Virgo/KAGRA S230627c: ATLAS information on the ZTF candidates
  63. ZTF23aaoohpy/AT2023lcr: further SAO RAS observations
  64. ATLAS23msn/ZTF23aaoohpy/AT2023lcr: Zeiss-1000 of Koshka observatory optical observations
  65. MAXI GRB 230623A: MASTER optical observations
  66. ZTF23aaoohpy/AT2023lcr: SAO RAS observations
  67. AT2023lcr: VLA radio detection
  68. ZTF23aaoohpy/AT2023lcr: Montarrenti Observatory optical observations
  69. ZTF23aaoohpy (AT2023lcr/ATLAS23msn): Swift/UVOT detection
  70. ZTF23aaoohpy/AT2023lc: Mondy optical observations
  71. AT2023lcr: Neil Gehrels Swift Observatory X-ray detection
  72. ZTF23aaoohpy/AT2023lcr: Keck/LRIS spectroscopy and redshift
  73. ZTF23aaoohpy/AT2023lcr: Xinglong-2.16m optical observations
  74. ZTF23aaoohpy/AT2023lcr: Liverpool Telescope detection
  75. ZTF23aaoohpy/AT2023lcr: OHP/T193 and OHP/T120 optical follow-up observations
  76. ZTF23aaoohpy/AT2023lcr: GOTO early optical observations and constraint
  77. GRB 230618A: Swift/UVOT Upper Limits
  78. GRB 230618A: KAIT Optical Observations
  79. GRB230618A: LCOGT Optical Observations
  80. LIGO/Virgo/KAGRA S230615az: T80S Search and Candidate Counterpart Identification
  81. LIGO/Virgo/KAGRA S230615az: Non-Detections of GROWTH-India Candidates from GECKO Optical Observations
  82. LIGO/Virgo/KAGRA S230615az: GOTO candidate counterparts
  83. GRB 230606A: LCOGT Optical Observations
  84. ZTF23aamxeqf/AT2023jxk: 1.3m DFOT Optical upper limit
  85. ZTF and GIT Observations of the Candidate Optical Afterglow AT2023jxk
  86. GRB 230606A: Gaoyazi/GOT optical upper limit
  87. GRB 230606A: BOOTES-5/JGT optical upper limit
  88. GRB 230606A: Swift/UVOT Upper Limits
  89. LIGO/Virgo/KAGRA S230518h: ATCA follow-up of candidate counterparts
  90. LIGO/Virgo/KAGRA S230518h: GECKO tiling observations with KMTNet
  91. LIGO/Virgo/KAGRA S230518h: ATLAS observations of the skymap
  92. LIGO/Virgo/KAGRA S230518h: Swope Search and Candidate Counterpart Identification
  93. Improved IPN triangulation of GRB 230512A
  94. GRB 230512A: Nanshan/NEXT non-detection of GRB afterglow candidate
  95. GRB 230512A: Liverpool Telescope observations
  96. GRB 230512A: GIT non detection of afterglow candidate
  97. GRB 230512A: Kitab possible afterglow candidate
  98. GRB 230510A: OHP/T193 and OHP/T120 optical observations
  99. GRB 230512A: GIT optical follow-up ZTF candidates
  100. GRB 230510A: GIT optical upper limits

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